diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0a79194..691cd56 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,7 @@ set(sources "src/main.cpp"
             "src/DrawData.cpp"
             "src/FontData.cpp"
             "src/ClientData.cpp"
+            "src/CollabPermissions.cpp"
             "src/GridManager.cpp"
             "src/WorldGrid.cpp"
             "src/TimePoint.cpp"
diff --git a/FORK.md b/FORK.md
index d907a46..4e07232 100644
--- a/FORK.md
+++ b/FORK.md
@@ -4,7 +4,7 @@ Upstream: [ErrorAtLine0/infinipaint](https://github.com/ErrorAtLine0/infinipaint
 **Public forge:** https://forgejo.fsociety00.cc/copilot/infinipaint  
 GitHub (`littlecodedragon/infinipaint`) is **private builder only** — not a public fork mirror. Source of truth stays on Forgejo.
 
-Save format: `INFPNT000008` / version `0.8.0-fork` (not network-compatible with stock 0.6.x peers).
+Save format: `INFPNT000009` / version `0.9.0-fork` (not network-compatible with stock 0.6.x peers).
 
 ## CI
 
@@ -33,4 +33,18 @@ Not automatic on import. Choose **Paste Image + Freistellen** from the canvas ri
 
 ## Fog of War / layer lock (host)
 
-In the layer panel (host / local file only): mark a leaf layer as **Fog of War layer** (must sit **above** the content it covers), then paint fog with brush/shapes on that layer. Players receive a **stripped** world — only objects **fully** covered by opaque fog (not merely overlapping) are omitted from join sync and from their save. Partially covered images stay. Moving or reshaping fog (or content under it) live-updates clients: newly covered objects are unloaded, revealed ones are sent again with their resources. The host file stays complete. Fog draws at the layer’s real alpha (1.0 = fully opaque for host and players). **Lock for players** blocks client edits on a normal layer; fog layers are always locked for players (move/edit/erase rejected on the host). Players also **cannot hide or fade** a fog layer (eye / alpha); only the host can toggle fog visibility, and the host rejects client DisplayData that would strip FoW.
+In the layer panel (host / local file only): mark a leaf layer as **Fog of War layer** (must sit **above** the content it covers), then paint fog with brush/shapes on that layer. Players receive a **stripped** world — only objects **fully** covered by opaque fog (not merely overlapping) are omitted from join sync and from their save. Partially covered images stay. Moving or reshaping fog (or content under it) live-updates clients: newly covered objects are unloaded, revealed ones are sent again with their resources. The host file stays complete. Fog draws at the layer’s real alpha (1.0 = fully opaque for host and players). **Lock for players** is a quick toggle that sets layer-default Draw/Move/Delete to Deny; fog layers are always locked for players (move/edit/erase rejected on the host). Players also **cannot hide or fade** a fog layer (eye / alpha); only the host can toggle fog visibility, and the host rejects client DisplayData that would strip FoW. FoW visibility is still global (not per-person).
+
+## Collab permissions (host)
+
+Rights: **Draw**, **Move**, **Delete**, **Hide**, **Layers** (create/reorder/delete layers). Each right is Allow / Deny / Inherit.
+
+Resolution (first concrete wins): Person×Layer override → Layer defaults → Person defaults → World default (Inherit at world = Allow).
+
+Host UI:
+
+- Player list → **Session Defaults…** (world / new-player / new-layer templates)
+- Player list → **Rights** per connected player (person defaults; copied from new-player template on join)
+- Layer panel (host): layer defaults + per-player overrides for the selected layer
+
+Clients cannot escalate their own ACL; host DisplayData/ClientData updates are sanitized.
diff --git a/src/CanvasComponents/CanvasComponentAllocator.cpp b/src/CanvasComponents/CanvasComponentAllocator.cpp
index 059b233..89dcaac 100644
--- a/src/CanvasComponents/CanvasComponentAllocator.cpp
+++ b/src/CanvasComponents/CanvasComponentAllocator.cpp
@@ -45,10 +45,10 @@ void CanvasComponentAllocator::register_class(World& world) {
         .writeUpdate = [](const CanvasComponentAllocator& o, cereal::PortableBinaryOutputArchive& a) {
             a(*o.comp);
         },
-        .readUpdate = [](CanvasComponentAllocator& o, cereal::PortableBinaryInputArchive& a, const std::shared_ptr<NetServer::ClientData>& c) {
-            // Host rejects client edits of fog/locked-layer components (still consume the payload).
-            if(c && o.comp && o.comp->compContainer && o.comp->compContainer->parentLayer
-               && o.comp->compContainer->parentLayer->is_player_edit_blocked()) {
+        .readUpdate = [&world](CanvasComponentAllocator& o, cereal::PortableBinaryInputArchive& a, const std::shared_ptr<NetServer::ClientData>& c) {
+            // Host rejects client edits without Draw on that layer (still consume the payload).
+            if(c && o.comp && o.comp->compContainer
+               && !world.drawProg.layerMan.client_may_modify_component(o.comp->compContainer, CollabRight::Draw)) {
                 auto junk = std::unique_ptr<CanvasComponent>(CanvasComponent::allocate_comp(o.comp->get_type()));
                 a(*junk);
                 return;
diff --git a/src/ClientData.cpp b/src/ClientData.cpp
index 76442e1..8c5ad4b 100644
--- a/src/ClientData.cpp
+++ b/src/ClientData.cpp
@@ -36,7 +36,8 @@ enum class ClientDataCommand : uint8_t {
     SET_WINDOW_SIZE,
     SET_CAM_COORDS,
     SEND_CHAT_MESSAGE,
-    SET_GRID_SIZE
+    SET_GRID_SIZE,
+    SET_PERSON_DEFAULTS
 };
 
 ClientData::ClientData() {
@@ -54,6 +55,7 @@ void ClientData::set_from_init_struct(const InitStruct& initStruct) {
     cursorColor = initStruct.cursorColor;
     displayName = initStruct.displayName;
     gridSize = initStruct.gridSize;
+    personDefaults = initStruct.personDefaults;
 }
 
 void ClientData::register_class(World& world) {
@@ -92,6 +94,11 @@ void ClientData::register_class(World& world) {
                     }
                     break;
                 }
+                case ClientDataCommand::SET_PERSON_DEFAULTS:
+                    a(o->personDefaults);
+                    world.drawProg.layerMan.ensure_editing_layer_is_editable();
+                    world.set_to_layout_gui_if_focus();
+                    break;
             }
         },
         .writeConstructorFuncServer = default_serialize_write_func<ClientData>,
@@ -141,6 +148,20 @@ void ClientData::register_class(World& world) {
                     });
                     break;
                 }
+                case ClientDataCommand::SET_PERSON_DEFAULTS: {
+                    // Only the host may change ACLs — junk-consume client attempts.
+                    CollabPermissionSet incoming;
+                    a(incoming);
+                    if(c)
+                        break;
+                    o->personDefaults = incoming;
+                    o.send_server_update_to_all_clients(RELIABLE_COMMAND_CHANNEL, [](const NetObjTemporaryPtr<ClientData>& o, cereal::PortableBinaryOutputArchive & a) {
+                        a(ClientDataCommand::SET_PERSON_DEFAULTS, o->personDefaults);
+                    });
+                    world.drawProg.layerMan.ensure_editing_layer_is_editable();
+                    world.set_to_layout_gui_if_focus();
+                    break;
+                }
             }
         },
     });
@@ -187,6 +208,15 @@ void ClientData::scale_up_step(const NetworkingObjects::NetObjTemporaryPtr<Clien
     });
 }
 
+void ClientData::set_person_defaults(const NetworkingObjects::NetObjTemporaryPtr<ClientData>& o, const CollabPermissionSet& defaults) {
+    if(o->personDefaults == defaults)
+        return;
+    o->personDefaults = defaults;
+    o.send_update_to_all(RELIABLE_COMMAND_CHANNEL, [](const NetObjTemporaryPtr<ClientData>& o, cereal::PortableBinaryOutputArchive & a) {
+        a(ClientDataCommand::SET_PERSON_DEFAULTS, o->personDefaults);
+    });
+}
+
 void ClientData::set_display_name(const std::string& newDisplayName) {
     displayName = newDisplayName;
 }
@@ -219,6 +249,14 @@ const Vector3f& ClientData::get_cursor_color() const {
     return cursorColor;
 }
 
+const CollabPermissionSet& ClientData::get_person_defaults() const {
+    return personDefaults;
+}
+
+CollabPermissionSet& ClientData::person_defaults_mut() {
+    return personDefaults;
+}
+
 void ClientData::draw_cursor(SkCanvas* canvas, const DrawData& drawData) const {
     if((drawData.cam.c.inverseScale << 10) > camCoords.inverseScale && drawData.clampDrawMinimum < camCoords.inverseScale) {
         canvas->save();
diff --git a/src/ClientData.hpp b/src/ClientData.hpp
index 3a4f1da..01aacac 100644
--- a/src/ClientData.hpp
+++ b/src/ClientData.hpp
@@ -19,6 +19,7 @@
 #pragma once
 #include <Helpers/Serializers.hpp>
 #include "CoordSpaceHelper.hpp"
+#include "CollabPermissions.hpp"
 #include <Helpers/NetworkingObjects/NetObjTemporaryPtr.hpp>
 #include <Helpers/NetworkingObjects/NetObjManager.hpp>
 
@@ -32,6 +33,7 @@ class ClientData {
             Vector3f cursorColor = {1.0f, 1.0f, 1.0f};
             std::string displayName;
             uint32_t gridSize = 0;
+            CollabPermissionSet personDefaults = CollabPermissionSet::all_inherit();
         };
 
         ClientData();
@@ -42,6 +44,8 @@ class ClientData {
         static void set_camera_coords(const NetworkingObjects::NetObjTemporaryPtr<ClientData>& o, const CoordSpaceHelper& newCoords);
         static void send_chat_message(const NetworkingObjects::NetObjTemporaryPtr<ClientData>& o, World& world, const std::string& chatMessage);
         static void scale_up_step(const NetworkingObjects::NetObjTemporaryPtr<ClientData>& o, World& world);
+        /** Host-only: push person-default ACL to all peers. */
+        static void set_person_defaults(const NetworkingObjects::NetObjTemporaryPtr<ClientData>& o, const CollabPermissionSet& defaults);
         void set_display_name(const std::string& newDisplayName);
         void set_cursor_color(const Vector3f& newCursorColor);
 
@@ -51,11 +55,13 @@ class ClientData {
         uint32_t get_grid_size() const;
         const std::string& get_display_name() const;
         const Vector3f& get_cursor_color() const;
+        const CollabPermissionSet& get_person_defaults() const;
+        CollabPermissionSet& person_defaults_mut();
 
         void draw_cursor(SkCanvas* canvas, const DrawData& drawData) const;
 
         template <typename Archive> void serialize(Archive& a) {
-            a(camCoords, windowSize, cursorPos, cursorColor, displayName, gridSize);
+            a(camCoords, windowSize, cursorPos, cursorColor, displayName, gridSize, personDefaults);
         }
     private:
         void set_from_init_struct(const InitStruct& initStruct);
@@ -66,5 +72,6 @@ class ClientData {
         Vector3f cursorColor;
         std::string displayName;
         uint32_t gridSize;
+        CollabPermissionSet personDefaults;
 };
 
diff --git a/src/CollabPermissions.cpp b/src/CollabPermissions.cpp
new file mode 100644
index 0000000..b2963c4
--- /dev/null
+++ b/src/CollabPermissions.cpp
@@ -0,0 +1,114 @@
+#include "CollabPermissions.hpp"
+
+CollabTriState CollabPermissionSet::get(CollabRight right) const {
+    switch(right) {
+        case CollabRight::Draw: return draw;
+        case CollabRight::Move: return move;
+        case CollabRight::Delete: return erase;
+        case CollabRight::Hide: return hide;
+        case CollabRight::ManageLayers: return manageLayers;
+        case CollabRight::COUNT: break;
+    }
+    return CollabTriState::Inherit;
+}
+
+void CollabPermissionSet::set(CollabRight right, CollabTriState state) {
+    switch(right) {
+        case CollabRight::Draw: draw = state; break;
+        case CollabRight::Move: move = state; break;
+        case CollabRight::Delete: erase = state; break;
+        case CollabRight::Hide: hide = state; break;
+        case CollabRight::ManageLayers: manageLayers = state; break;
+        case CollabRight::COUNT: break;
+    }
+}
+
+bool CollabPermissionSet::any_concrete() const {
+    return draw != CollabTriState::Inherit
+        || move != CollabTriState::Inherit
+        || erase != CollabTriState::Inherit
+        || hide != CollabTriState::Inherit
+        || manageLayers != CollabTriState::Inherit;
+}
+
+CollabPermissionSet CollabPermissionSet::all_allow() {
+    CollabPermissionSet s;
+    s.draw = CollabTriState::Allow;
+    s.move = CollabTriState::Allow;
+    s.erase = CollabTriState::Allow;
+    s.hide = CollabTriState::Allow;
+    s.manageLayers = CollabTriState::Allow;
+    return s;
+}
+
+CollabPermissionSet CollabPermissionSet::all_inherit() {
+    return CollabPermissionSet{};
+}
+
+CollabPermissionSet CollabPermissionSet::content_deny() {
+    CollabPermissionSet s;
+    s.draw = CollabTriState::Deny;
+    s.move = CollabTriState::Deny;
+    s.erase = CollabTriState::Deny;
+    return s;
+}
+
+bool collab_resolve_allow(
+    CollabRight right,
+    const CollabPermissionSet* personLayerOverride,
+    const CollabPermissionSet& layerDefaults,
+    const CollabPermissionSet& personDefaults,
+    const CollabPermissionSet& worldDefault)
+{
+    auto pick = [&](const CollabPermissionSet& set) -> CollabTriState {
+        return set.get(right);
+    };
+    if(personLayerOverride) {
+        CollabTriState s = pick(*personLayerOverride);
+        if(s != CollabTriState::Inherit)
+            return s == CollabTriState::Allow;
+    }
+    {
+        CollabTriState s = pick(layerDefaults);
+        if(s != CollabTriState::Inherit)
+            return s == CollabTriState::Allow;
+    }
+    {
+        CollabTriState s = pick(personDefaults);
+        if(s != CollabTriState::Inherit)
+            return s == CollabTriState::Allow;
+    }
+    CollabTriState s = pick(worldDefault);
+    // World Inherit → Allow (open by default).
+    return s != CollabTriState::Deny;
+}
+
+const char* collab_right_label(CollabRight right) {
+    switch(right) {
+        case CollabRight::Draw: return "Draw";
+        case CollabRight::Move: return "Move";
+        case CollabRight::Delete: return "Delete";
+        case CollabRight::Hide: return "Hide";
+        case CollabRight::ManageLayers: return "Layers";
+        case CollabRight::COUNT: break;
+    }
+    return "?";
+}
+
+const char* collab_tristate_label(CollabTriState state) {
+    switch(state) {
+        case CollabTriState::Inherit: return "Inherit";
+        case CollabTriState::Allow: return "Allow";
+        case CollabTriState::Deny: return "Deny";
+    }
+    return "?";
+}
+
+CollabTriState collab_cycle_tristate(CollabTriState state) {
+    switch(state) {
+        case CollabTriState::Inherit: return CollabTriState::Allow;
+        case CollabTriState::Allow: return CollabTriState::Deny;
+        case CollabTriState::Deny: return CollabTriState::Inherit;
+    }
+    return CollabTriState::Inherit;
+}
diff --git a/src/CollabPermissions.hpp b/src/CollabPermissions.hpp
new file mode 100644
index 0000000..5f5e0c5
--- /dev/null
+++ b/src/CollabPermissions.hpp
@@ -0,0 +1,77 @@
+/*
+ * InfiniPaint (fork)
+ * Collab ACL: World → Person → Layer → Person×Layer (Allow/Deny/Inherit)
+ */
+#pragma once
+
+#include <cstdint>
+#include <map>
+#include <string>
+#include <cereal/types/map.hpp>
+#include <cereal/types/string.hpp>
+
+enum class CollabRight : uint8_t {
+    Draw = 0,
+    Move,
+    Delete,
+    Hide,
+    ManageLayers,
+    COUNT
+};
+
+enum class CollabTriState : uint8_t {
+    Inherit = 0,
+    Allow = 1,
+    Deny = 2
+};
+
+struct CollabPermissionSet {
+    CollabTriState draw = CollabTriState::Inherit;
+    CollabTriState move = CollabTriState::Inherit;
+    CollabTriState erase = CollabTriState::Inherit;
+    CollabTriState hide = CollabTriState::Inherit;
+    CollabTriState manageLayers = CollabTriState::Inherit;
+
+    CollabTriState get(CollabRight right) const;
+    void set(CollabRight right, CollabTriState state);
+    bool any_concrete() const;
+
+    static CollabPermissionSet all_allow();
+    static CollabPermissionSet all_inherit();
+    static CollabPermissionSet content_deny(); // Draw/Move/Delete Deny, rest Inherit
+
+    template <typename Archive>
+    void serialize(Archive& a) {
+        a(draw, move, erase, hide, manageLayers);
+    }
+
+    bool operator==(const CollabPermissionSet&) const = default;
+};
+
+struct CollabSessionDefaults {
+    // Concrete fallback when everything inherits (Inherit treated as Allow).
+    CollabPermissionSet worldDefault = CollabPermissionSet::all_allow();
+    // Copied onto ClientData when a player joins.
+    CollabPermissionSet newPlayerDefaults = CollabPermissionSet::all_inherit();
+    // Copied onto new layers' DisplayData.layerDefaults.
+    CollabPermissionSet newLayerDefaults = CollabPermissionSet::all_inherit();
+
+    template <typename Archive>
+    void serialize(Archive& a) {
+        a(worldDefault, newPlayerDefaults, newLayerDefaults);
+    }
+
+    bool operator==(const CollabSessionDefaults&) const = default;
+};
+
+/** Resolve Allow/Deny for peer on a layer. Host callers should short-circuit before this. */
+bool collab_resolve_allow(
+    CollabRight right,
+    const CollabPermissionSet* personLayerOverride, // nullable
+    const CollabPermissionSet& layerDefaults,
+    const CollabPermissionSet& personDefaults,
+    const CollabPermissionSet& worldDefault);
+
+const char* collab_right_label(CollabRight right);
+const char* collab_tristate_label(CollabTriState state);
+CollabTriState collab_cycle_tristate(CollabTriState state);
diff --git a/src/DrawingProgram/DrawingProgram.cpp b/src/DrawingProgram/DrawingProgram.cpp
index 97fa77b..485b2fb 100644
--- a/src/DrawingProgram/DrawingProgram.cpp
+++ b/src/DrawingProgram/DrawingProgram.cpp
@@ -48,6 +48,8 @@
 #include <chrono>
 #include "../CanvasComponents/ImageCanvasComponent.hpp"
 #include "Layers/DrawingProgramLayer.hpp"
+#include "../CollabPermissions.hpp"
+#include <Helpers/NetworkingObjects/DelayUpdateSerializedClassManager.hpp>
 #include "../ImagePreprocess.hpp"
 #include <Helpers/Random.hpp>
 #include <cereal/types/utility.hpp>
@@ -308,7 +310,44 @@ std::optional<InputManager::TextBoxStartInfo> DrawingProgram::get_text_box_start
     return drawTool->get_text_box_start_info();
 }
 
+void DrawingProgram::register_collab_defaults_class(World& world) {
+    world.delayedUpdateObjectManager.register_class<CollabSessionDefaults>(world.netObjMan, NetworkingObjects::DelayUpdateSerializedClassManager::CustomConstructors<CollabSessionDefaults>{
+        .readUpdate = [](CollabSessionDefaults& o, cereal::PortableBinaryInputArchive& a, const std::shared_ptr<NetServer::ClientData>& c) {
+            CollabSessionDefaults incoming;
+            a(incoming);
+            // Clients cannot escalate session defaults.
+            if(c)
+                return;
+            o = incoming;
+        },
+        .postUpdateFunc = [&world](CollabSessionDefaults&) {
+            world.drawProg.layerMan.ensure_editing_layer_is_editable();
+            world.set_to_layout_gui_if_focus();
+        }
+    });
+}
+
+void DrawingProgram::ensure_collab_defaults() {
+    if(!collabDefaults)
+        collabDefaults = world.netObjMan.make_obj<CollabSessionDefaults>();
+}
+
+const CollabSessionDefaults& DrawingProgram::collab_defaults() const {
+    static const CollabSessionDefaults kFallback{};
+    return collabDefaults ? *collabDefaults : kFallback;
+}
+
+void DrawingProgram::set_collab_defaults(const CollabSessionDefaults& defaults) {
+    ensure_collab_defaults();
+    if(*collabDefaults == defaults)
+        return;
+    *collabDefaults = defaults;
+    world.delayedUpdateObjectManager.send_update_to_all<CollabSessionDefaults>(collabDefaults, false);
+    layerMan.ensure_editing_layer_is_editable();
+}
+
 void DrawingProgram::server_init_no_file() {
+    ensure_collab_defaults();
     layerMan.server_init_no_file();
 }
 
@@ -322,10 +361,13 @@ void DrawingProgram::scale_up(const WorldScalar& scaleUpAmount) {
 }
 
 void DrawingProgram::write_components_server(cereal::PortableBinaryOutputArchive& a) {
+    ensure_collab_defaults();
+    collabDefaults.write_create_message(a);
     layerMan.write_components_server(a);
 }
 
 void DrawingProgram::read_components_client(cereal::PortableBinaryInputArchive& a) {
+    collabDefaults = world.netObjMan.read_create_message<CollabSessionDefaults>(a, nullptr);
     layerMan.read_components_client(a);
     drawCache.build({});
 }
@@ -335,6 +377,7 @@ void DrawingProgram::init_server_callbacks() {
         std::vector<std::pair<NetworkingObjects::NetObjID, CoordSpaceHelper>> transforms;
         message(transforms);
 
+        world.currentNetUpdateClient = client;
         auto clientData = world.netObjMan.get_obj_temporary_ref_from_id<ClientData>(NetworkingObjects::NetObjID(client->customID));
         if(clientData->get_grid_size() < world.ownClientData->get_grid_size()) {
             WorldScalar scaleUpAmount = get_canvas_scale_up_amount(world.ownClientData->get_grid_size(), clientData->get_grid_size());
@@ -349,12 +392,13 @@ void DrawingProgram::init_server_callbacks() {
             auto objPtr = world.netObjMan.get_obj_temporary_ref_from_id<CanvasComponentContainer>(netID);
             if(!objPtr)
                 continue;
-            if(!layerMan.client_may_modify_component(objPtr.get())) {
+            if(!layerMan.client_may_modify_component(objPtr.get(), CollabRight::Move)) {
                 rejectedRestore.emplace_back(netID, objPtr->coords);
                 continue;
             }
             allowed.emplace_back(netID, coord);
         }
+        world.currentNetUpdateClient = nullptr;
         if(!allowed.empty()) {
             process_transform_message(allowed);
             world.netServer->send_items_to_all_clients(RELIABLE_COMMAND_CHANNEL, CLIENT_TRANSFORM_MANY_COMPONENTS, allowed);
@@ -377,15 +421,16 @@ void DrawingProgram::init_server_callbacks() {
     world.netServer->add_recv_callback(SERVER_SET_COMPONENT_GROUP_IDS, [&](std::shared_ptr<NetServer::ClientData> client, cereal::PortableBinaryInputArchive& message) {
         std::vector<std::pair<NetworkingObjects::NetObjID, uint64_t>> groupIds;
         message(groupIds);
-        (void)client;
+        world.currentNetUpdateClient = client;
         std::vector<std::pair<NetworkingObjects::NetObjID, uint64_t>> allowed;
         allowed.reserve(groupIds.size());
         for(auto& [netID, groupId] : groupIds) {
             auto objPtr = world.netObjMan.get_obj_temporary_ref_from_id<CanvasComponentContainer>(netID);
-            if(!objPtr || !layerMan.client_may_modify_component(objPtr.get()))
+            if(!objPtr || !layerMan.client_may_modify_component(objPtr.get(), CollabRight::Move))
                 continue;
             allowed.emplace_back(netID, groupId);
         }
+        world.currentNetUpdateClient = nullptr;
         if(allowed.empty())
             return;
         process_group_id_message(allowed);
@@ -466,7 +511,7 @@ void DrawingProgram::send_transforms_for(const std::vector<CanvasComponentContai
         for(auto& obj : objsToSendTransformsFor) {
             if(!obj || !obj->obj)
                 continue;
-            if(!world.netObjMan.is_server() && !layerMan.client_may_modify_component(obj->obj.get()))
+            if(!world.netObjMan.is_server() && !layerMan.own_peer_may(CollabRight::Move, obj->obj->parentLayer))
                 continue;
             transforms.emplace_back(obj->obj.get_net_id(), obj->obj->coords);
         }
@@ -1166,11 +1211,16 @@ void DrawingProgram::draw_drag_circle(SkCanvas* canvas, const Vector2f& sPos, co
 void DrawingProgram::load_file(cereal::PortableBinaryInputArchive& a, VersionNumber version) {
     if(version >= VersionNumber(0, 6, 0))
         a(controls.lockedCameraScale);
+    ensure_collab_defaults();
+    if(version >= VersionNumber(0, 9, 0))
+        a(*collabDefaults);
     layerMan.load_file(a, version);
 }
 
 void DrawingProgram::save_file(cereal::PortableBinaryOutputArchive& a) const {
     a(controls.lockedCameraScale);
+    const_cast<DrawingProgram*>(this)->ensure_collab_defaults();
+    a(*collabDefaults);
     layerMan.save_file(a);
 }
 
diff --git a/src/DrawingProgram/DrawingProgram.hpp b/src/DrawingProgram/DrawingProgram.hpp
index 9138a4b..4285ca7 100644
--- a/src/DrawingProgram/DrawingProgram.hpp
+++ b/src/DrawingProgram/DrawingProgram.hpp
@@ -37,6 +37,7 @@
 #include <Helpers/NetworkingObjects/NetObjOrderedList.hpp>
 #include "Layers/DrawingProgramLayerManager.hpp"
 #include "DrawingProgramSelection.hpp"
+#include "../CollabPermissions.hpp"
 
 class World;
 class PhoneDrawingProgramScreen;
@@ -71,6 +72,12 @@ class DrawingProgram {
 
         DrawingProgramCache drawCache;
         DrawingProgramLayerManager layerMan;
+        /** Host-owned session ACL defaults (world / new player / new layer). */
+        NetworkingObjects::NetObjOwnerPtr<CollabSessionDefaults> collabDefaults;
+        void ensure_collab_defaults();
+        const CollabSessionDefaults& collab_defaults() const;
+        void set_collab_defaults(const CollabSessionDefaults& defaults);
+        static void register_collab_defaults_class(World& world);
 
         Vector4f* get_foreground_color_ptr();
         void switch_to_tool(DrawingProgramToolType newToolType, bool force = false);
diff --git a/src/DrawingProgram/Layers/DrawingProgramLayer.cpp b/src/DrawingProgram/Layers/DrawingProgramLayer.cpp
index 994de1f..7ef51c3 100644
--- a/src/DrawingProgram/Layers/DrawingProgramLayer.cpp
+++ b/src/DrawingProgram/Layers/DrawingProgramLayer.cpp
@@ -40,9 +40,10 @@ void DrawingProgramLayer::set_component_list_callbacks(DrawingProgramLayerListIt
         if(c->obj->get_comp().get_type() == CanvasComponentType::IMAGE)
             layerMan.drawP.updateableComponents.emplace(&(*c));
 
-        // Live fog / lock enforcement on host
+        // Live ACL / fog enforcement on host
         if(layerMan.addToCacheOnComponentInsert && layerMan.drawP.world.netServer) {
-            if(layerMan.drawP.world.currentNetUpdateClient && layerListItem.is_player_edit_blocked()) {
+            if(layerMan.drawP.world.currentNetUpdateClient
+               && !layerMan.current_net_client_may(CollabRight::Draw, &layerListItem)) {
                 layerMan.defer_reject_component(&layerListItem, c->obj.get_net_id());
                 return;
             }
diff --git a/src/DrawingProgram/Layers/DrawingProgramLayerListItem.cpp b/src/DrawingProgram/Layers/DrawingProgramLayerListItem.cpp
index 6c5d419..a849c61 100644
--- a/src/DrawingProgram/Layers/DrawingProgramLayerListItem.cpp
+++ b/src/DrawingProgram/Layers/DrawingProgramLayerListItem.cpp
@@ -19,11 +19,13 @@
 #include "DrawingProgramLayerListItem.hpp"
 #include "DrawingProgramLayerFolder.hpp"
 #include <cereal/types/string.hpp>
+#include <cereal/types/map.hpp>
 #include "DrawingProgramLayer.hpp"
 #include "FogStripper.hpp"
 #include "../../World.hpp"
 #include "../../MainProgram.hpp"
 #include "SerializedBlendMode.hpp"
+#include "../../DrawingProgram/DrawingProgram.hpp"
 
 using namespace NetworkingObjects;
 
@@ -179,17 +181,39 @@ DrawingProgramLayer& DrawingProgramLayerListItem::get_layer() const {
     return *layerData;
 }
 
+void DrawingProgramLayerListItem::DisplayData::migrate_player_locked_into_defaults() {
+    if(playerLocked && !fogLayer)
+        layerDefaults = CollabPermissionSet::content_deny();
+}
+
+void DrawingProgramLayerListItem::DisplayData::sync_player_locked_from_defaults() {
+    if(fogLayer) {
+        playerLocked = true;
+        return;
+    }
+    playerLocked = layerDefaults.draw == CollabTriState::Deny
+        && layerDefaults.move == CollabTriState::Deny
+        && layerDefaults.erase == CollabTriState::Deny;
+}
+
 void DrawingProgramLayerListItem::load_file(cereal::PortableBinaryInputArchive& a, VersionNumber version, DrawingProgramLayerManager& layerMan) {
     nameData = layerMan.drawP.world.netObjMan.make_obj<NameData>();
     a(*nameData);
 
     displayData = layerMan.drawP.world.netObjMan.make_obj<DisplayData>();
-    if(version >= VersionNumber(0, 8, 0)) {
+    if(version >= VersionNumber(0, 9, 0)) {
         a(*displayData);
-        // Normalize cereal bools (non-0/1 bytes must not stick as "true" forever).
         displayData->visible = displayData->visible ? true : false;
         displayData->playerLocked = displayData->playerLocked ? true : false;
         displayData->fogLayer = displayData->fogLayer ? true : false;
+        displayData->sync_player_locked_from_defaults();
+    }
+    else if(version >= VersionNumber(0, 8, 0)) {
+        a(displayData->alpha, displayData->visible, displayData->blendMode, displayData->playerLocked, displayData->fogLayer);
+        displayData->visible = displayData->visible ? true : false;
+        displayData->playerLocked = displayData->playerLocked ? true : false;
+        displayData->fogLayer = displayData->fogLayer ? true : false;
+        displayData->migrate_player_locked_into_defaults();
     }
     else {
         a(displayData->alpha, displayData->visible, displayData->blendMode);
@@ -262,6 +286,8 @@ void DrawingProgramLayerListItem::set_alpha(DrawingProgramLayerManager& layerMan
     // Players must not fade fog out — same authority as visibility.
     if(is_fog_layer() && !FogStripper::world_is_host(layerMan.drawP.world))
         return;
+    if(!FogStripper::world_is_host(layerMan.drawP.world) && !layerMan.own_peer_may(CollabRight::Hide, this))
+        return;
     if(displayData && displayData->alpha != newAlpha) {
         displayData->alpha = newAlpha;
         layerMan.drawP.drawCache.clear_own_cached_surfaces();
@@ -277,6 +303,8 @@ void DrawingProgramLayerListItem::set_visible(DrawingProgramLayerManager& layerM
     // Fog of War is host-controlled; clients hiding it would sync and strip FoW for everyone.
     if(is_fog_layer() && !FogStripper::world_is_host(layerMan.drawP.world))
         return;
+    if(!FogStripper::world_is_host(layerMan.drawP.world) && !layerMan.own_peer_may(CollabRight::Hide, this))
+        return;
     if(displayData && displayData->visible != newVisible) {
         displayData->visible = newVisible;
         layerMan.drawP.drawCache.clear_own_cached_surfaces();
@@ -304,12 +332,23 @@ void DrawingProgramLayerListItem::set_player_locked(DrawingProgramLayerManager&
     if(!displayData)
         return;
     bool newLocked = locked || displayData->fogLayer;
-    if(displayData->playerLocked != newLocked) {
-        displayData->playerLocked = newLocked;
-        layerMan.drawP.drawCache.clear_own_cached_surfaces();
-        layerMan.drawP.world.delayedUpdateObjectManager.send_update_to_all<DisplayData>(displayData, false);
-        layerMan.refresh_fog_client_projection();
+    CollabPermissionSet nextDefaults = displayData->layerDefaults;
+    if(newLocked)
+        nextDefaults = CollabPermissionSet::content_deny();
+    else if(displayData->playerLocked) {
+        // Unlock: clear content Deny back to Inherit for Draw/Move/Delete.
+        nextDefaults.draw = CollabTriState::Inherit;
+        nextDefaults.move = CollabTriState::Inherit;
+        nextDefaults.erase = CollabTriState::Inherit;
     }
+    if(displayData->playerLocked == newLocked && displayData->layerDefaults == nextDefaults)
+        return;
+    displayData->playerLocked = newLocked;
+    displayData->layerDefaults = nextDefaults;
+    layerMan.drawP.drawCache.clear_own_cached_surfaces();
+    layerMan.drawP.world.delayedUpdateObjectManager.send_update_to_all<DisplayData>(displayData, false);
+    layerMan.refresh_fog_client_projection();
+    layerMan.ensure_editing_layer_is_editable();
 }
 
 bool DrawingProgramLayerListItem::get_player_locked() const {
@@ -335,6 +374,55 @@ bool DrawingProgramLayerListItem::is_player_edit_blocked() const {
     return is_fog_layer() || get_player_locked();
 }
 
+const CollabPermissionSet& DrawingProgramLayerListItem::get_layer_defaults() const {
+    static const CollabPermissionSet kInherit = CollabPermissionSet::all_inherit();
+    return displayData ? displayData->layerDefaults : kInherit;
+}
+
+void DrawingProgramLayerListItem::set_layer_defaults(DrawingProgramLayerManager& layerMan, const CollabPermissionSet& defaults) const {
+    if(!displayData || displayData->layerDefaults == defaults)
+        return;
+    displayData->layerDefaults = defaults;
+    displayData->sync_player_locked_from_defaults();
+    layerMan.drawP.world.delayedUpdateObjectManager.send_update_to_all<DisplayData>(displayData, false);
+    layerMan.ensure_editing_layer_is_editable();
+}
+
+const std::map<std::string, CollabPermissionSet>& DrawingProgramLayerListItem::get_person_layer_overrides() const {
+    static const std::map<std::string, CollabPermissionSet> kEmpty;
+    return displayData ? displayData->personOverrides : kEmpty;
+}
+
+void DrawingProgramLayerListItem::set_person_layer_override(DrawingProgramLayerManager& layerMan, const std::string& displayName, const CollabPermissionSet& overrides) const {
+    if(!displayData || displayName.empty())
+        return;
+    if(!overrides.any_concrete()) {
+        clear_person_layer_override(layerMan, displayName);
+        return;
+    }
+    auto it = displayData->personOverrides.find(displayName);
+    if(it != displayData->personOverrides.end() && it->second == overrides)
+        return;
+    displayData->personOverrides[displayName] = overrides;
+    layerMan.drawP.world.delayedUpdateObjectManager.send_update_to_all<DisplayData>(displayData, false);
+    layerMan.ensure_editing_layer_is_editable();
+}
+
+void DrawingProgramLayerListItem::clear_person_layer_override(DrawingProgramLayerManager& layerMan, const std::string& displayName) const {
+    if(!displayData)
+        return;
+    if(displayData->personOverrides.erase(displayName) == 0)
+        return;
+    layerMan.drawP.world.delayedUpdateObjectManager.send_update_to_all<DisplayData>(displayData, false);
+    layerMan.ensure_editing_layer_is_editable();
+}
+
+void DrawingProgramLayerListItem::apply_new_layer_permission_defaults(DrawingProgramLayerManager& layerMan) const {
+    if(!displayData || is_folder())
+        return;
+    set_layer_defaults(layerMan, layerMan.drawP.collab_defaults().newLayerDefaults);
+}
+
 void DrawingProgramLayerListItem::set_metainfo(DrawingProgramLayerManager& layerMan, const DrawingProgramLayerListItemMetaInfo& metaInfo) {
     set_blend_mode(layerMan, metaInfo.blendMode);
     set_alpha(layerMan, metaInfo.alpha);
@@ -403,7 +491,7 @@ void DrawingProgramLayerListItem::register_class(World& w) {
         .readUpdate = [](DisplayData& o, cereal::PortableBinaryInputArchive& a, const std::shared_ptr<NetServer::ClientData>& c) {
             DisplayData incoming;
             a(incoming);
-            // Client→host: never allow stripping fog, unlocking, hiding, or fading fog.
+            // Client→host: never allow stripping fog, unlocking, hiding, fading fog, or escalating ACL.
             if(c) {
                 if(o.fogLayer || incoming.fogLayer) {
                     incoming.fogLayer = true;
@@ -415,8 +503,11 @@ void DrawingProgramLayerListItem::register_class(World& w) {
                     incoming.fogLayer = false;
                     incoming.playerLocked = o.playerLocked;
                 }
+                incoming.layerDefaults = o.layerDefaults;
+                incoming.personOverrides = o.personOverrides;
             }
             o = incoming;
+            o.sync_player_locked_from_defaults();
         },
         .postUpdateFunc = [&](DisplayData& o) {
             (void)o;
diff --git a/src/DrawingProgram/Layers/DrawingProgramLayerListItem.hpp b/src/DrawingProgram/Layers/DrawingProgramLayerListItem.hpp
index 9f13dab..2b99695 100644
--- a/src/DrawingProgram/Layers/DrawingProgramLayerListItem.hpp
+++ b/src/DrawingProgram/Layers/DrawingProgramLayerListItem.hpp
@@ -20,10 +20,12 @@
 #include <Helpers/NetworkingObjects/NetObjManager.hpp>
 #include <Helpers/NetworkingObjects/NetObjOrderedList.hpp>
 #include <Helpers/NetworkingObjects/DelayUpdateSerializedClassManager.hpp>
+#include <map>
 #include <unordered_set>
 #include "DrawingProgramLayerFolder.hpp"
 #include "DrawingProgramLayer.hpp"
 #include "SerializedBlendMode.hpp"
+#include "../../CollabPermissions.hpp"
 #include "../../CanvasComponents/CanvasComponentContainer.hpp"
 
 class DrawingProgramLayerFolder;
@@ -89,6 +91,14 @@ class DrawingProgramLayerListItem {
         // Fog layers are always treated as player-locked for edit checks.
         bool is_player_edit_blocked() const;
 
+        const CollabPermissionSet& get_layer_defaults() const;
+        void set_layer_defaults(DrawingProgramLayerManager& layerMan, const CollabPermissionSet& defaults) const;
+        const std::map<std::string, CollabPermissionSet>& get_person_layer_overrides() const;
+        void set_person_layer_override(DrawingProgramLayerManager& layerMan, const std::string& displayName, const CollabPermissionSet& overrides) const;
+        void clear_person_layer_override(DrawingProgramLayerManager& layerMan, const std::string& displayName) const;
+        /** Apply session new-layer defaults (call after create). */
+        void apply_new_layer_permission_defaults(DrawingProgramLayerManager& layerMan) const;
+
         void set_metainfo(DrawingProgramLayerManager& layerMan, const DrawingProgramLayerListItemMetaInfo& metaInfo);
         DrawingProgramLayerListItemMetaInfo get_metainfo() const;
 
@@ -115,9 +125,13 @@ class DrawingProgramLayerListItem {
             SerializedBlendMode blendMode = SerializedBlendMode::BLEND_SRC_OVER;
             bool playerLocked = false;
             bool fogLayer = false;
+            CollabPermissionSet layerDefaults = CollabPermissionSet::all_inherit();
+            std::map<std::string, CollabPermissionSet> personOverrides;
             template <typename Archive> void serialize(Archive& a) {
-                a(alpha, visible, blendMode, playerLocked, fogLayer);
+                a(alpha, visible, blendMode, playerLocked, fogLayer, layerDefaults, personOverrides);
             }
+            void migrate_player_locked_into_defaults();
+            void sync_player_locked_from_defaults();
         };
         NetworkingObjects::NetObjOwnerPtr<NameData> nameData;
         NetworkingObjects::NetObjOwnerPtr<DisplayData> displayData;
diff --git a/src/DrawingProgram/Layers/DrawingProgramLayerManager.cpp b/src/DrawingProgram/Layers/DrawingProgramLayerManager.cpp
index d1a6947..2ae95ab 100644
--- a/src/DrawingProgram/Layers/DrawingProgramLayerManager.cpp
+++ b/src/DrawingProgram/Layers/DrawingProgramLayerManager.cpp
@@ -19,6 +19,7 @@
 #include "DrawingProgramLayerManager.hpp"
 #include "FogStripper.hpp"
 #include "../../World.hpp"
+#include "../../ClientData.hpp"
 #include "Helpers/NetworkingObjects/NetObjID.hpp"
 #include "Helpers/NetworkingObjects/NetObjOrderedList.hpp"
 #include "Helpers/NetworkingObjects/NetObjOwnerPtr.decl.hpp"
@@ -291,20 +292,88 @@ void DrawingProgramLayerManager::disable_add_to_cache_and_commit_update_block(co
     addToCacheOnComponentInsert = true;
 }
 
-bool DrawingProgramLayerManager::can_current_peer_edit_layer(const DrawingProgramLayerListItem* layer) const {
+bool DrawingProgramLayerManager::peer_may(CollabRight right, const DrawingProgramLayerListItem* layer, const ClientData* peer) const {
     if(!layer)
         return false;
+    if(FogStripper::world_is_host(drawP.world) && (!peer || peer == drawP.world.ownClientData.get()))
+        return true;
+    // Content rights on fog layers are always denied for non-host peers.
+    if(layer->is_fog_layer()
+       && (right == CollabRight::Draw || right == CollabRight::Move || right == CollabRight::Delete))
+        return false;
+    if(right == CollabRight::Hide && layer->is_fog_layer())
+        return false;
+
+    CollabPermissionSet personDefaults = CollabPermissionSet::all_inherit();
+    const CollabPermissionSet* personLayer = nullptr;
+    std::string peerName;
+    if(peer) {
+        personDefaults = peer->get_person_defaults();
+        peerName = peer->get_display_name();
+        auto& overrides = layer->get_person_layer_overrides();
+        auto it = overrides.find(peerName);
+        if(it != overrides.end())
+            personLayer = &it->second;
+    }
+    return collab_resolve_allow(
+        right,
+        personLayer,
+        layer->get_layer_defaults(),
+        personDefaults,
+        drawP.collab_defaults().worldDefault);
+}
+
+bool DrawingProgramLayerManager::own_peer_may(CollabRight right, const DrawingProgramLayerListItem* layer) const {
     if(FogStripper::world_is_host(drawP.world))
         return true;
-    return !layer->is_player_edit_blocked();
+    return peer_may(right, layer, drawP.world.ownClientData.get());
+}
+
+bool DrawingProgramLayerManager::peer_may_manage_layers(const ClientData* peer) const {
+    if(FogStripper::world_is_host(drawP.world) && (!peer || peer == drawP.world.ownClientData.get()))
+        return true;
+    // ManageLayers is not layer-scoped — resolve with empty layer defaults / no person×layer.
+    CollabPermissionSet personDefaults = peer ? peer->get_person_defaults() : CollabPermissionSet::all_inherit();
+    return collab_resolve_allow(
+        CollabRight::ManageLayers,
+        nullptr,
+        CollabPermissionSet::all_inherit(),
+        personDefaults,
+        drawP.collab_defaults().worldDefault);
+}
+
+bool DrawingProgramLayerManager::current_net_client_may(CollabRight right, const DrawingProgramLayerListItem* layer) const {
+    if(!drawP.world.currentNetUpdateClient)
+        return true; // local/host-originated
+    auto peer = drawP.world.netObjMan.get_obj_temporary_ref_from_id<ClientData>(
+        NetworkingObjects::NetObjID(drawP.world.currentNetUpdateClient->customID));
+    if(!peer)
+        return false;
+    if(right == CollabRight::ManageLayers)
+        return peer_may_manage_layers(peer.get());
+    return peer_may(right, layer, peer.get());
+}
+
+bool DrawingProgramLayerManager::can_current_peer_edit_layer(const DrawingProgramLayerListItem* layer) const {
+    return own_peer_may(CollabRight::Draw, layer);
 }
 
 bool DrawingProgramLayerManager::client_may_modify_component(const CanvasComponentContainer* comp) const {
+    return client_may_modify_component(comp, CollabRight::Draw);
+}
+
+bool DrawingProgramLayerManager::client_may_modify_component(const CanvasComponentContainer* comp, CollabRight right) const {
     // Host-side authority check for CLIENT messages — must NOT use can_current_peer_edit_layer
     // (that always returns true on the host).
     if(!comp || !comp->parentLayer)
         return false;
-    return !comp->parentLayer->is_player_edit_blocked();
+    if(!drawP.world.currentNetUpdateClient) {
+        // Transform callbacks set currentNetUpdateClient; fallback: legacy lock/fog.
+        if(comp->parentLayer->is_player_edit_blocked())
+            return false;
+        return true;
+    }
+    return current_net_client_may(right, comp->parentLayer);
 }
 
 void DrawingProgramLayerManager::ensure_editing_layer_is_editable() {
diff --git a/src/DrawingProgram/Layers/DrawingProgramLayerManager.hpp b/src/DrawingProgram/Layers/DrawingProgramLayerManager.hpp
index 6c22977..a0bcda3 100644
--- a/src/DrawingProgram/Layers/DrawingProgramLayerManager.hpp
+++ b/src/DrawingProgram/Layers/DrawingProgramLayerManager.hpp
@@ -19,9 +19,12 @@
 #pragma once
 #include "DrawingProgramLayerListItem.hpp"
 #include "DrawingProgramLayerManagerGUI.hpp"
+#include "../../CollabPermissions.hpp"
 #include <unordered_set>
 #include <vector>
 
+class ClientData;
+
 class DrawingProgramLayerManager {
     private:
         DrawingProgram& drawP;
@@ -89,6 +92,11 @@ class DrawingProgramLayerManager {
 
         bool can_current_peer_edit_layer(const DrawingProgramLayerListItem* layer) const;
         bool client_may_modify_component(const CanvasComponentContainer* comp) const;
+        bool client_may_modify_component(const CanvasComponentContainer* comp, CollabRight right) const;
+        bool own_peer_may(CollabRight right, const DrawingProgramLayerListItem* layer) const;
+        bool peer_may(CollabRight right, const DrawingProgramLayerListItem* layer, const ClientData* peer) const;
+        bool peer_may_manage_layers(const ClientData* peer) const;
+        bool current_net_client_may(CollabRight right, const DrawingProgramLayerListItem* layer) const;
         void ensure_editing_layer_is_editable();
         /** Host: recompute fog coverage and erase/reveal (+ resources) on clients. */
         void refresh_fog_client_projection();
diff --git a/src/DrawingProgram/Layers/DrawingProgramLayerManagerGUI.cpp b/src/DrawingProgram/Layers/DrawingProgramLayerManagerGUI.cpp
index 8d44030..32a6020 100644
--- a/src/DrawingProgram/Layers/DrawingProgramLayerManagerGUI.cpp
+++ b/src/DrawingProgram/Layers/DrawingProgramLayerManagerGUI.cpp
@@ -26,6 +26,8 @@
 #include "Helpers/ConvertVec.hpp"
 #include "Helpers/NetworkingObjects/NetObjOrderedList.hpp"
 #include "SerializedBlendMode.hpp"
+#include "../../CollabPermissions.hpp"
+#include "../../ClientData.hpp"
 
 #include "../../GUIStuff/ElementHelpers/TextLabelHelpers.hpp"
 #include "../../GUIStuff/ElementHelpers/ButtonHelpers.hpp"
@@ -150,20 +152,22 @@ void DrawingProgramLayerManagerGUI::setup_list_gui() {
                             .drawType = SelectableButton::DrawType::TRANSPARENT_ALL,
                             .size = TreeListing::ENTRY_HEIGHT,
                             .onClick = [&, layer, fogVisibilityLocked] {
-                                if(!fogVisibilityLocked)
+                                if(!fogVisibilityLocked && layerMan.own_peer_may(CollabRight::Hide, layer.get()))
                                     layer->set_visible(layerMan, !layer->get_visible());
                             }
                         });
                     });
-                    gui.set_z_index_keep_clipping_region(gui.get_z_index() + 1, [&] {
-                        svg_icon_button(gui, "delete button", "data/icons/trash.svg", {
-                            .drawType = SelectableButton::DrawType::TRANSPARENT_ALL,
-                            .size = TreeListing::ENTRY_HEIGHT,
-                            .onClick = [&, objIndex] {
-                                remove_layer(objIndex);
-                            }
+                    if(layerMan.peer_may_manage_layers(world.ownClientData.get())) {
+                        gui.set_z_index_keep_clipping_region(gui.get_z_index() + 1, [&] {
+                            svg_icon_button(gui, "delete button", "data/icons/trash.svg", {
+                                .drawType = SelectableButton::DrawType::TRANSPARENT_ALL,
+                                .size = TreeListing::ENTRY_HEIGHT,
+                                .onClick = [&, objIndex] {
+                                    remove_layer(objIndex);
+                                }
+                            });
                         });
-                    });
+                    }
                 },
                 .onDoubleClick = [&](const TreeListingObjIndexList& objIndex) {
                     auto layer = get_layer_from_obj_index(objIndex);
@@ -196,6 +200,8 @@ void DrawingProgramLayerManagerGUI::setup_list_gui() {
                     }
                 },
                 .moveObj = [&](const std::vector<TreeListingObjIndexList>& objectIndicesTreeListing, const TreeListingObjIndexList& newObjIndexTreeListing) {
+                    if(!layerMan.peer_may_manage_layers(world.ownClientData.get()))
+                        return;
                     NetObjID listObj;
                     size_t index;
                     struct ParentObjectIDPair {
@@ -396,32 +402,34 @@ void DrawingProgramLayerManagerGUI::setup_list_gui() {
             });
         }
 
-        left_to_right_line_layout(gui, [&]() {
-            input_text(gui, "input new name", &nameForNew, {
-                .onEnter = [&] {
-                    auto newLayerObjInfo = create_layer(new DrawingProgramLayerListItem(world.netObjMan, nameForNew, false));
-                    layerMan.editingLayer = newLayerObjInfo->obj;
-                    layerMan.drawP.world.main.g.gui.set_to_layout();
-                }
-            });
+        if(layerMan.peer_may_manage_layers(world.ownClientData.get())) {
+            left_to_right_line_layout(gui, [&]() {
+                input_text(gui, "input new name", &nameForNew, {
+                    .onEnter = [&] {
+                        auto newLayerObjInfo = create_layer(new DrawingProgramLayerListItem(world.netObjMan, nameForNew, false));
+                        layerMan.editingLayer = newLayerObjInfo->obj;
+                        layerMan.drawP.world.main.g.gui.set_to_layout();
+                    }
+                });
 
-            svg_icon_button(gui, "create new layer", "data/icons/plusbold.svg", {
-                .size = SMALL_BUTTON_SIZE,
-                .onClick = [&] {
-                    auto newLayerObjInfo = create_layer(new DrawingProgramLayerListItem(world.netObjMan, nameForNew, false));
-                    layerMan.editingLayer = newLayerObjInfo->obj;
-                    layerMan.drawP.world.main.g.gui.set_to_layout();
-                }
-            });
+                svg_icon_button(gui, "create new layer", "data/icons/plusbold.svg", {
+                    .size = SMALL_BUTTON_SIZE,
+                    .onClick = [&] {
+                        auto newLayerObjInfo = create_layer(new DrawingProgramLayerListItem(world.netObjMan, nameForNew, false));
+                        layerMan.editingLayer = newLayerObjInfo->obj;
+                        layerMan.drawP.world.main.g.gui.set_to_layout();
+                    }
+                });
 
-            svg_icon_button(gui, "create new folder", "data/icons/folderbold.svg", {
-                .size = SMALL_BUTTON_SIZE,
-                .onClick = [&] {
-                    auto newFolderObjInfo = create_layer(new DrawingProgramLayerListItem(world.netObjMan, nameForNew, true));
-                    newFolderObjInfo->obj->get_folder().isFolderOpen = true;
-                }
+                svg_icon_button(gui, "create new folder", "data/icons/folderbold.svg", {
+                    .size = SMALL_BUTTON_SIZE,
+                    .onClick = [&] {
+                        auto newFolderObjInfo = create_layer(new DrawingProgramLayerListItem(world.netObjMan, nameForNew, true));
+                        newFolderObjInfo->obj->get_folder().isFolderOpen = true;
+                    }
+                });
             });
-        });
+        }
 
         auto editingLayerLock = editingLayer.lock();
         if(editingLayerLock) {
@@ -479,6 +487,67 @@ void DrawingProgramLayerManagerGUI::setup_list_gui() {
                             if(layer)
                                 layer->set_player_locked(layerMan, !layer->get_player_locked());
                         });
+                    text_label(gui, "Layer defaults (Inherit → Person → World)");
+                    {
+                        const CollabPermissionSet& layerSet = editingLayerLock->get_layer_defaults();
+                        left_to_right_line_layout(gui, [&]() {
+                            for(uint8_t i = 0; i < static_cast<uint8_t>(CollabRight::COUNT); i++) {
+                                CollabRight right = static_cast<CollabRight>(i);
+                                gui.new_id(200 + i, [&] {
+                                    std::string label = std::string(collab_right_label(right)) + ":"
+                                        + collab_tristate_label(layerSet.get(right));
+                                    text_button(gui, "layer perm", label.c_str(), {
+                                        .onClick = [&, right] {
+                                            auto layer = editingLayer.lock();
+                                            if(!layer)
+                                                return;
+                                            CollabPermissionSet next = layer->get_layer_defaults();
+                                            next.set(right, collab_cycle_tristate(next.get(right)));
+                                            layer->set_layer_defaults(layerMan, next);
+                                        }
+                                    });
+                                });
+                            }
+                        });
+                    }
+                    if(world.clients) {
+                        text_label(gui, "Per-player overrides on this layer");
+                        size_t pnum = 0;
+                        for(auto& client : world.clients->get_data()) {
+                            if(client == world.ownClientData)
+                                continue;
+                            gui.new_id(300 + pnum++, [&] {
+                                const std::string pname = client->get_display_name();
+                                text_label(gui, pname);
+                                CollabPermissionSet overrideSet = CollabPermissionSet::all_inherit();
+                                auto it = editingLayerLock->get_person_layer_overrides().find(pname);
+                                if(it != editingLayerLock->get_person_layer_overrides().end())
+                                    overrideSet = it->second;
+                                left_to_right_line_layout(gui, [&]() {
+                                    for(uint8_t i = 0; i < static_cast<uint8_t>(CollabRight::COUNT); i++) {
+                                        CollabRight right = static_cast<CollabRight>(i);
+                                        gui.new_id(i, [&] {
+                                            std::string label = std::string(collab_right_label(right)) + ":"
+                                                + collab_tristate_label(overrideSet.get(right));
+                                            text_button(gui, "player layer perm", label.c_str(), {
+                                                .onClick = [&, right, pname] {
+                                                    auto layer = editingLayer.lock();
+                                                    if(!layer)
+                                                        return;
+                                                    CollabPermissionSet next = CollabPermissionSet::all_inherit();
+                                                    auto found = layer->get_person_layer_overrides().find(pname);
+                                                    if(found != layer->get_person_layer_overrides().end())
+                                                        next = found->second;
+                                                    next.set(right, collab_cycle_tristate(next.get(right)));
+                                                    layer->set_person_layer_override(layerMan, pname, next);
+                                                }
+                                            });
+                                        });
+                                    }
+                                });
+                            });
+                        }
+                    }
                 }
                 else
                     text_label(gui, "Fog layers are always locked for players.");
@@ -563,6 +632,7 @@ NetworkingObjects::NetObjOrderedListIterator<DrawingProgramLayerListItem> Drawin
 
     auto insertedLayerPair = create_in_proper_position(newItem);
     auto& it = insertedLayerPair.second;
+    it->obj->apply_new_layer_permission_defaults(layerMan);
     world.undo.push(std::make_unique<AddLayerWorldUndoAction>(std::make_unique<DrawingProgramLayerListItemUndoData>(it->obj->get_undo_data(world.undo)), it->pos, world.undo.get_undoid_from_netid(insertedLayerPair.first), world.undo.get_undoid_from_netid(it->obj.get_net_id())));
     world.main.g.gui.set_to_layout();
     refresh_gui_data();
diff --git a/src/Toolbar.cpp b/src/Toolbar.cpp
index 9cc1f4d..145fcdc 100644
--- a/src/Toolbar.cpp
+++ b/src/Toolbar.cpp
@@ -36,6 +36,8 @@
 #include "RichText/TextStyleModifier.hpp"
 #include "VersionConstants.hpp"
 #include "World.hpp"
+#include "ClientData.hpp"
+#include "CollabPermissions.hpp"
 #include <SDL3/SDL_dialog.h>
 #include <SDL3/SDL_filesystem.h>
 #include <SDL3/SDL_render.h>
@@ -1205,33 +1207,84 @@ void Toolbar::color_palette(const char* id, Vector4f* color, const std::function
 }
 
 void Toolbar::player_list() {
+    using namespace GUIStuff;
+    using namespace ElementHelpers;
     auto& gui = main.g.gui;
+    auto& world = *main.world;
+    auto& layerMan = world.drawProg.layerMan;
 
-    center_obstructing_window_gui("player client list", CLAY_SIZING_FIT(500), CLAY_SIZING_FIT(0), [&] {
+    auto draw_perm_buttons = [&](const char* rowId, const CollabPermissionSet& shown,
+                                 const std::function<void(CollabRight)>& cycleRight) {
+        gui.new_id(rowId, [&] {
+            left_to_right_line_layout(gui, [&]() {
+                for(uint8_t i = 0; i < static_cast<uint8_t>(CollabRight::COUNT); i++) {
+                    CollabRight right = static_cast<CollabRight>(i);
+                    gui.new_id(i, [&] {
+                        std::string label = std::string(collab_right_label(right)) + ":"
+                            + collab_tristate_label(shown.get(right));
+                        text_button(gui, "perm", label.c_str(), {
+                            .onClick = [cycleRight, right] {
+                                cycleRight(right);
+                            }
+                        });
+                    });
+                }
+            });
+        });
+    };
+
+    center_obstructing_window_gui("player client list", CLAY_SIZING_FIT(640), CLAY_SIZING_FIT(0), [&] {
         gui.new_id("client list", [&] {
             text_label_centered(gui, "Player List");
-            if(!main.world->clientStillConnecting) {
-                if(main.world->netServer) {
+            if(!world.clientStillConnecting) {
+                if(world.netServer) {
                     text_button(gui, "force all jump to host", "Bring Everyone Here", {
                         .wide = true,
                         .onClick = [&] {
-                            main.world->drawProg.force_clients_to_own_view();
+                            world.drawProg.force_clients_to_own_view();
                         }
                     });
+                    text_button(gui, "toggle session defaults", collabSessionDefaultsOpen ? "Hide Session Defaults" : "Session Defaults…", {
+                        .wide = true,
+                        .onClick = [&] {
+                            collabSessionDefaultsOpen = !collabSessionDefaultsOpen;
+                        }
+                    });
+                    if(collabSessionDefaultsOpen) {
+                        const CollabSessionDefaults& cur = world.drawProg.collab_defaults();
+                        text_label(gui, "World default (fallback when everything inherits)");
+                        draw_perm_buttons("world default row", cur.worldDefault, [&](CollabRight right) {
+                            auto d = world.drawProg.collab_defaults();
+                            d.worldDefault.set(right, collab_cycle_tristate(d.worldDefault.get(right)));
+                            world.drawProg.set_collab_defaults(d);
+                        });
+                        text_label(gui, "New player defaults (copied on join)");
+                        draw_perm_buttons("new player default row", cur.newPlayerDefaults, [&](CollabRight right) {
+                            auto d = world.drawProg.collab_defaults();
+                            d.newPlayerDefaults.set(right, collab_cycle_tristate(d.newPlayerDefaults.get(right)));
+                            world.drawProg.set_collab_defaults(d);
+                        });
+                        text_label(gui, "New layer defaults (copied on create)");
+                        draw_perm_buttons("new layer default row", cur.newLayerDefaults, [&](CollabRight right) {
+                            auto d = world.drawProg.collab_defaults();
+                            d.newLayerDefaults.set(right, collab_cycle_tristate(d.newLayerDefaults.get(right)));
+                            world.drawProg.set_collab_defaults(d);
+                        });
+                    }
                 }
                 left_to_right_line_layout(gui, [&]() {
                     CLAY_AUTO_ID({
                         .layout = {
                             .sizing = {.width = CLAY_SIZING_FIXED(20), .height = CLAY_SIZING_FIXED(20)}
                         },
-                        .backgroundColor = convert_vec4<Clay_Color>(SkColor4f{main.world->ownClientData->get_cursor_color().x(), main.world->ownClientData->get_cursor_color().y(), main.world->ownClientData->get_cursor_color().z(), 1.0f}),
+                        .backgroundColor = convert_vec4<Clay_Color>(SkColor4f{world.ownClientData->get_cursor_color().x(), world.ownClientData->get_cursor_color().y(), world.ownClientData->get_cursor_color().z(), 1.0f}),
                         .cornerRadius = CLAY_CORNER_RADIUS(3)
                     }) {}
-                    text_label(gui, main.world->ownClientData->get_display_name());
+                    text_label(gui, world.ownClientData->get_display_name() + " (you / host)");
                 });
                 size_t num = 0;
-                for(auto& client : main.world->clients->get_data()) {
-                    if(client != main.world->ownClientData) {
+                for(auto& client : world.clients->get_data()) {
+                    if(client != world.ownClientData) {
                         gui.new_id(num++, [&] {
                             left_to_right_line_layout(gui, [&]() {
                                 CLAY_AUTO_ID({
@@ -1244,15 +1297,40 @@ void Toolbar::player_list() {
                                 text_label(gui, client->get_display_name());
                                 CLAY_AUTO_ID({.layout = {.sizing = {.width = CLAY_SIZING_GROW(0), .height = CLAY_SIZING_GROW(0)}}}) {}
                                 text_button(gui, "teleport button", "Jump To", { .onClick = [&] {
-                                    main.world->drawData.cam.smooth_move_to(*main.world, client->get_cam_coords(), client->get_window_size());
+                                    world.drawData.cam.smooth_move_to(world, client->get_cam_coords(), client->get_window_size());
                                 }});
+                                if(world.netServer) {
+                                    text_button(gui, "perms button", "Rights", {
+                                        .onClick = [&, name = client->get_display_name()] {
+                                            if(collabPermsExpandedPlayer == name)
+                                                collabPermsExpandedPlayer.clear();
+                                            else
+                                                collabPermsExpandedPlayer = name;
+                                        }
+                                    });
+                                }
                             });
+                            if(world.netServer && collabPermsExpandedPlayer == client->get_display_name()) {
+                                text_label(gui, "Person defaults (Inherit → World)");
+                                NetworkingObjects::NetObjID clientId = client.get_net_id();
+                                draw_perm_buttons("person defaults", client->get_person_defaults(), [&, clientId](CollabRight right) {
+                                    auto peer = world.netObjMan.get_obj_temporary_ref_from_id<ClientData>(clientId);
+                                    if(!peer)
+                                        return;
+                                    CollabPermissionSet next = peer->get_person_defaults();
+                                    next.set(right, collab_cycle_tristate(next.get(right)));
+                                    ClientData::set_person_defaults(peer, next);
+                                    layerMan.ensure_editing_layer_is_editable();
+                                });
+                            }
                         });
                     }
                 }
             }
             text_button(gui, "close list", "Done", { .wide = true, .onClick = [&] {
                 playerMenuOpen = false;
+                collabSessionDefaultsOpen = false;
+                collabPermsExpandedPlayer.clear();
             }});
         });
     });
diff --git a/src/Toolbar.hpp b/src/Toolbar.hpp
index 05d4438..a243e8a 100644
--- a/src/Toolbar.hpp
+++ b/src/Toolbar.hpp
@@ -153,6 +153,8 @@ class Toolbar {
         bool menuPopUpOpen = false;
         bool optionsMenuOpen = false;
         bool playerMenuOpen = false;
+        bool collabSessionDefaultsOpen = false;
+        std::string collabPermsExpandedPlayer;
 
         float finalCalculatedGuiScale = 1.0f;
 
diff --git a/src/VersionConstants.cpp b/src/VersionConstants.cpp
index 2138525..1540978 100644
--- a/src/VersionConstants.cpp
+++ b/src/VersionConstants.cpp
@@ -32,6 +32,7 @@ VersionNumber header_to_version_number(const std::string& header) {
         m["INFPNT000006"] = VersionNumber(0, 6, 0);
         m["INFPNT000007"] = VersionNumber(0, 7, 0);
         m["INFPNT000008"] = VersionNumber(0, 8, 0);
+        m["INFPNT000009"] = VersionNumber(0, 9, 0);
     }
     auto it = m.find(header);
     if(it == m.end())
diff --git a/src/VersionConstants.hpp b/src/VersionConstants.hpp
index d01c73f..4dfb13d 100644
--- a/src/VersionConstants.hpp
+++ b/src/VersionConstants.hpp
@@ -28,7 +28,7 @@ namespace VersionConstants {
     VersionNumber header_to_version_number(const std::string& header); 
 
     constexpr int SAVEFILE_HEADER_LEN = 12; // DO NOT CHANGE THIS HEADER LENGTH
-    const std::string CURRENT_SAVEFILE_HEADER = "INFPNT000008"; // Change whenever the save file is incompatible with the previous version
-    const std::string CURRENT_VERSION_STRING = "0.8.0-fork";
-    constexpr VersionNumber CURRENT_VERSION_NUMBER(0, 8, 0);
+    const std::string CURRENT_SAVEFILE_HEADER = "INFPNT000009"; // Change whenever the save file is incompatible with the previous version
+    const std::string CURRENT_VERSION_STRING = "0.9.0-fork";
+    constexpr VersionNumber CURRENT_VERSION_NUMBER(0, 9, 0);
 }
diff --git a/src/World.cpp b/src/World.cpp
index 3cecd46..0a23226 100644
--- a/src/World.cpp
+++ b/src/World.cpp
@@ -70,6 +70,7 @@ World::World(MainProgram& initMain, const CustomEvents::OpenInfiniPaintFileEvent
     saveThumbnail = worldInfo.saveThumbnail;
 
     init_net_obj_type_list();
+    drawProg.ensure_collab_defaults();
     netObjMan.set_netobj_destroy_callback([&undo = undo](const NetworkingObjects::NetObjID& idToDestroy) {
         undo.remove_by_netid(idToDestroy);
     });
@@ -135,6 +136,7 @@ void World::init_net_obj_type_list() {
     NetworkingObjects::register_ordered_list_class<CanvasComponentContainer>(netObjMan);
     DrawingProgramLayerListItem::register_class(*this);
     NetworkingObjects::register_ordered_list_class<DrawingProgramLayerListItem>(netObjMan);
+    DrawingProgram::register_collab_defaults_class(*this);
     canvasTheme.register_class();
     ClientData::register_class(*this);
     NetworkingObjects::register_unordered_set_class<ClientData>(netObjMan);
@@ -433,6 +435,7 @@ void World::start_hosting(const std::string& initNetSource, const std::string& s
         newClientData.camCoords = ownClientData->get_cam_coords();
         newClientData.windowSize = ownClientData->get_window_size();
         newClientData.gridSize = ownClientData->get_grid_size();
+        newClientData.personDefaults = drawProg.collab_defaults().newPlayerDefaults;
 
         NetworkingObjects::NetObjTemporaryPtr<ClientData> clientDataObjPtr = clients->emplace_direct(clients, newClientData);
         client->customID = clientDataObjPtr.get_net_id().data;