diff --git a/src/exporter.rs b/src/exporter.rs
index 43b5270..01d6296 100644
--- a/src/exporter.rs
+++ b/src/exporter.rs
@@ -587,7 +587,9 @@ fn build_svg(layout: &DungeonLayout, settings: &UiSettings) -> String {
             ("rgb(220,70,70)", None)
         };
 
-        if let Some((x1, y1, x2, y2)) = door_line_points(&g, door.from, door.to, door.width) {
+        if let Some((x1, y1, x2, y2)) =
+            door_line_points(&g, door.from, door.to, door_render_width(door))
+        {
             if let Some(pattern) = dash {
                 let _ = writeln!(
                     s,
@@ -938,7 +940,8 @@ fn draw_door(
     color: (u8, u8, u8, u8),
     style: DoorStyle,
 ) {
-    let Some((x1, y1, x2, y2)) = door_line_points(g, door.from, door.to, door.width) else {
+    let Some((x1, y1, x2, y2)) = door_line_points(g, door.from, door.to, door_render_width(door))
+    else {
         return;
     };
     draw_line(pixmap, x1, y1, x2, y2, width, color, style);
@@ -1097,7 +1100,7 @@ fn door_edges_for(door: &Door, cols: usize, rows: usize) -> Vec<((usize, usize),
         return edges;
     }
 
-    let width = door.width.max(1) as isize;
+    let width = door_render_width(door).max(1) as isize;
     let min_offset = -((width - 1) / 2);
     let max_offset = width / 2;
 
@@ -1127,3 +1130,11 @@ fn door_edges_for(door: &Door, cols: usize, rows: usize) -> Vec<((usize, usize),
 
     edges
 }
+
+fn door_render_width(door: &Door) -> usize {
+    if door.span_width {
+        door.width.max(1)
+    } else {
+        1
+    }
+}
diff --git a/src/layout.rs b/src/layout.rs
index 5384142..8d6e743 100644
--- a/src/layout.rs
+++ b/src/layout.rs
@@ -31,6 +31,7 @@ pub struct Door {
     pub from: (usize, usize),
     pub to: (usize, usize),
     pub width: usize,
+    pub span_width: bool,
     pub locked: bool,
     pub archway: bool,
 }
@@ -245,6 +246,7 @@ pub fn apply_doors(
                     from: edge.0,
                     to: edge.1,
                     width: corridor.width.max(1),
+                    span_width: true,
                     locked: place_door && rng.next_f32() <= locked,
                     archway: !place_door,
                 });
@@ -258,6 +260,7 @@ pub fn apply_doors(
                     from: edge.0,
                     to: edge.1,
                     width: corridor.width.max(1),
+                    span_width: true,
                     locked: place_door && rng.next_f32() <= locked,
                     archway: !place_door,
                 });
@@ -276,6 +279,7 @@ pub fn apply_doors(
                         from: edge.0,
                         to: edge.1,
                         width: 1,
+                        span_width: false,
                         locked: rng.next_f32() <= locked,
                         archway: false,
                     });
@@ -288,6 +292,7 @@ pub fn apply_doors(
                         from: edge.0,
                         to: edge.1,
                         width: 1,
+                        span_width: false,
                         locked: rng.next_f32() <= locked,
                         archway: false,
                     });
diff --git a/src/main.rs b/src/main.rs
index db9464f..f9b96d3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -33,6 +33,7 @@ struct DungeonApp {
     resize_state: Option<RoomResizeState>,
     hover_room_idx: Option<usize>,
     hover_corridor_idx: Option<usize>,
+    hover_door_idx: Option<usize>,
 }
 
 impl Default for DungeonApp {
@@ -62,6 +63,7 @@ impl Default for DungeonApp {
             resize_state: None,
             hover_room_idx: None,
             hover_corridor_idx: None,
+            hover_door_idx: None,
         }
     }
 }
@@ -193,6 +195,7 @@ impl eframe::App for DungeonApp {
             self.draw_add_overlay(&painter, &geometry);
             self.draw_resize_overlay(&painter, &geometry);
             self.draw_corridor_hover_overlay(&painter, &geometry);
+            self.draw_door_hover_overlay(&painter, &geometry);
         });
     }
 }
@@ -445,6 +448,16 @@ impl DungeonApp {
                     self.settings.add_tool = AddTool::None;
                 }
             }
+            AddTool::Door | AddTool::LockedDoor => {
+                self.add_corridor_drag = None;
+                if response.clicked()
+                    && let Some(pointer_pos) = response.interact_pointer_pos()
+                {
+                    let locked = self.settings.add_tool == AddTool::LockedDoor;
+                    self.add_door_at_pointer(pointer_pos, geometry, locked);
+                    self.settings.add_tool = AddTool::None;
+                }
+            }
             AddTool::None => {
                 self.add_corridor_drag = None;
             }
@@ -552,17 +565,35 @@ impl DungeonApp {
         let Some(pointer_pos) = ctx.pointer_hover_pos() else {
             self.hover_room_idx = None;
             self.hover_corridor_idx = None;
+            self.hover_door_idx = None;
             return;
         };
+        if let Some(edge) = self.door_edge_at_pointer(pointer_pos, geometry) {
+            let target = normalized_edge(edge.0, edge.1);
+            self.hover_door_idx = self.layout.doors.iter().position(|d| {
+                door_edges_for(d, self.settings.cols, self.settings.rows)
+                    .iter()
+                    .any(|e| normalized_edge(e.0, e.1) == target)
+            });
+            if self.hover_door_idx.is_some() {
+                self.hover_room_idx = None;
+                self.hover_corridor_idx = None;
+                return;
+            }
+        }
+
         if let Some((room_idx, _, _)) = self.room_at_pointer(pointer_pos, geometry) {
             self.hover_room_idx = Some(room_idx);
             self.hover_corridor_idx = None;
+            self.hover_door_idx = None;
         } else {
             self.hover_room_idx = None;
             if let Some(corridor_drag) = self.corridor_drag_at_pointer(pointer_pos, geometry) {
                 self.hover_corridor_idx = Some(corridor_drag.corridor_index);
+                self.hover_door_idx = None;
             } else {
                 self.hover_corridor_idx = None;
+                self.hover_door_idx = None;
             }
         }
     }
@@ -777,7 +808,71 @@ impl DungeonApp {
         }
     }
 
+    fn draw_door_hover_overlay(&self, painter: &egui::Painter, geometry: &GridGeometry) {
+        let Some(idx) = self.hover_door_idx else {
+            return;
+        };
+        let Some(door) = self.layout.doors.get(idx) else {
+            return;
+        };
+        let color = Color32::from_gray(200);
+        let stroke = Stroke::new(2.0, color);
+        draw_door_line(
+            painter,
+            geometry,
+            door.from,
+            door.to,
+            door_render_width(door),
+            stroke,
+            DoorLineStyle::LongDash,
+        );
+    }
+
     fn delete_at_pointer(&mut self, pointer_pos: egui::Pos2, geometry: &GridGeometry) {
+        if let Some(edge) = self.door_edge_at_pointer(pointer_pos, geometry) {
+            let target = normalized_edge(edge.0, edge.1);
+            if let Some(idx) = self.layout.doors.iter().position(|d| {
+                door_edges_for(d, self.settings.cols, self.settings.rows)
+                    .iter()
+                    .any(|e| normalized_edge(e.0, e.1) == target)
+            }) {
+                let edges = door_edges_for(
+                    &self.layout.doors[idx],
+                    self.settings.cols,
+                    self.settings.rows,
+                );
+                let mut spawned = Vec::new();
+                for edge in edges {
+                    if normalized_edge(edge.0, edge.1) == target {
+                        continue;
+                    }
+                    if self
+                        .layout
+                        .doors
+                        .iter()
+                        .any(|d| normalized_edge(d.from, d.to) == normalized_edge(edge.0, edge.1))
+                    {
+                        continue;
+                    }
+                    spawned.push(layout::Door {
+                        from: edge.0,
+                        to: edge.1,
+                        width: 1,
+                        span_width: false,
+                        locked: false,
+                        archway: true,
+                    });
+                }
+                let door = &mut self.layout.doors[idx];
+                door.locked = false;
+                door.archway = true;
+                door.width = 1;
+                door.span_width = false;
+                self.layout.doors.extend(spawned);
+                return;
+            }
+        }
+
         if let Some((room_idx, _, _)) = self.room_at_pointer(pointer_pos, geometry) {
             self.delete_room(room_idx);
             return;
@@ -811,6 +906,132 @@ impl DungeonApp {
         self.drag_state = None;
         self.refresh_doors();
     }
+
+    fn add_door_at_pointer(
+        &mut self,
+        pointer_pos: egui::Pos2,
+        geometry: &GridGeometry,
+        locked: bool,
+    ) {
+        let Some(edge) = self.door_edge_at_pointer(pointer_pos, geometry) else {
+            return;
+        };
+        let target = normalized_edge(edge.0, edge.1);
+        if let Some(idx) = self.layout.doors.iter().position(|d| {
+            door_edges_for(d, self.settings.cols, self.settings.rows)
+                .iter()
+                .any(|e| normalized_edge(e.0, e.1) == target)
+        }) {
+            let edges = door_edges_for(
+                &self.layout.doors[idx],
+                self.settings.cols,
+                self.settings.rows,
+            );
+            let mut spawned = Vec::new();
+            for edge in edges {
+                if normalized_edge(edge.0, edge.1) == target {
+                    continue;
+                }
+                if self
+                    .layout
+                    .doors
+                    .iter()
+                    .any(|d| normalized_edge(d.from, d.to) == normalized_edge(edge.0, edge.1))
+                {
+                    continue;
+                }
+                spawned.push(layout::Door {
+                    from: edge.0,
+                    to: edge.1,
+                    width: 1,
+                    span_width: false,
+                    locked: false,
+                    archway: true,
+                });
+            }
+            let door = &mut self.layout.doors[idx];
+            door.locked = locked;
+            door.archway = false;
+            door.width = 1;
+            door.span_width = false;
+            self.layout.doors.extend(spawned);
+            return;
+        }
+
+        let corridor_cells = corridor_cells(&self.layout, self.settings.cols, self.settings.rows);
+        let a_in_room = room_index_at_cell(&self.layout.rooms, edge.0).is_some();
+        let b_in_room = room_index_at_cell(&self.layout.rooms, edge.1).is_some();
+        let a_in_corridor = corridor_cells.contains(&edge.0);
+        let b_in_corridor = corridor_cells.contains(&edge.1);
+
+        if !(a_in_room ^ b_in_room) {
+            return;
+        }
+        if !(a_in_corridor ^ b_in_corridor) {
+            return;
+        }
+
+        self.layout.doors.push(layout::Door {
+            from: edge.0,
+            to: edge.1,
+            width: 1,
+            span_width: false,
+            locked,
+            archway: false,
+        });
+    }
+
+    fn door_edge_at_pointer(
+        &self,
+        pointer_pos: egui::Pos2,
+        geometry: &GridGeometry,
+    ) -> Option<((usize, usize), (usize, usize))> {
+        let (grid_x, grid_y) = pointer_to_grid(pointer_pos, geometry)?;
+        let cell_x = grid_x.floor() as isize;
+        let cell_y = grid_y.floor() as isize;
+        if cell_x < 0
+            || cell_y < 0
+            || cell_x >= self.settings.cols as isize
+            || cell_y >= self.settings.rows as isize
+        {
+            return None;
+        }
+
+        let fx = grid_x - grid_x.floor();
+        let fy = grid_y - grid_y.floor();
+        let left = fx;
+        let right = 1.0 - fx;
+        let top = fy;
+        let bottom = 1.0 - fy;
+
+        let mut candidates = [
+            (left, (cell_x - 1, cell_y), (cell_x, cell_y)),
+            (right, (cell_x + 1, cell_y), (cell_x, cell_y)),
+            (top, (cell_x, cell_y - 1), (cell_x, cell_y)),
+            (bottom, (cell_x, cell_y + 1), (cell_x, cell_y)),
+        ];
+        candidates.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap());
+        let (dist, a, b) = candidates[0];
+        if dist > 0.2 {
+            return None;
+        }
+
+        let (ax, ay) = a;
+        let (bx, by) = b;
+        if ax < 0
+            || ay < 0
+            || bx < 0
+            || by < 0
+            || ax >= self.settings.cols as isize
+            || bx >= self.settings.cols as isize
+            || ay >= self.settings.rows as isize
+            || by >= self.settings.rows as isize
+        {
+            return None;
+        }
+
+        Some(((ax as usize, ay as usize), (bx as usize, by as usize)))
+    }
 }
 
 #[derive(Debug, Clone)]
@@ -1117,7 +1338,7 @@ fn draw_layout(
             geometry,
             door.from,
             door.to,
-            door.width,
+            door_render_width(door),
             Stroke::new(door_width_px, color),
             style,
         );
@@ -1287,7 +1508,7 @@ fn door_edges_for(
         return edges;
     }
 
-    let width = door.width.max(1) as isize;
+    let width = door_render_width(door).max(1) as isize;
     let min_offset = -((width - 1) / 2);
     let max_offset = width / 2;
 
@@ -1318,6 +1539,14 @@ fn door_edges_for(
     edges
 }
 
+fn door_render_width(door: &layout::Door) -> usize {
+    if door.span_width {
+        door.width.max(1)
+    } else {
+        1
+    }
+}
+
 fn pointer_to_grid(pointer_pos: egui::Pos2, geometry: &GridGeometry) -> Option<(f32, f32)> {
     if !geometry.rect.contains(pointer_pos) {
         return None;
diff --git a/src/ui.rs b/src/ui.rs
index 76010e9..176f0d1 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -153,6 +153,8 @@ pub enum AddTool {
     None,
     Room,
     Corridor,
+    Door,
+    LockedDoor,
 }
 
 #[derive(Debug, Clone, Copy, Default)]
@@ -557,12 +559,20 @@ fn draw_add_tab(ui: &mut egui::Ui, settings: &mut UiSettings) {
     ui.horizontal(|ui| {
         ui.selectable_value(&mut settings.add_tool, AddTool::Room, "Add Room");
         ui.selectable_value(&mut settings.add_tool, AddTool::Corridor, "Add Corridor");
+        ui.selectable_value(&mut settings.add_tool, AddTool::Door, "Add Door");
+        ui.selectable_value(
+            &mut settings.add_tool,
+            AddTool::LockedDoor,
+            "Add Locked Door",
+        );
     });
 
     ui.add_space(6.0);
     match settings.add_tool {
         AddTool::Room => ui.label("Click to place a room at the grid cell."),
         AddTool::Corridor => ui.label("Click-drag to place a corridor between two cells."),
+        AddTool::Door => ui.label("Click a room/corridor edge to place a door."),
+        AddTool::LockedDoor => ui.label("Click a room/corridor edge to place a locked door."),
         AddTool::None => ui.label("Select a tool to add rooms or corridors."),
     };
 }