diff --git a/client/src/graphics/window.rs b/client/src/graphics/window.rs
index 43f512b5..49992096 100644
--- a/client/src/graphics/window.rs
+++ b/client/src/graphics/window.rs
@@ -266,6 +266,11 @@ impl Window {
                                 sim.toggle_no_clip();
                             }
                         }
+                        KeyCode::KeyB if state == ElementState::Pressed => {
+                            if let Some(sim) = self.sim.as_mut() {
+                                sim.debug_spawn_blinker();
+                            }
+                        }
                         KeyCode::F1 if state == ElementState::Pressed => {
                             self.gui_state.toggle_gui();
                         }
diff --git a/client/src/prediction.rs b/client/src/prediction.rs
index 5d9c5ab7..b7ee98c3 100644
--- a/client/src/prediction.rs
+++ b/client/src/prediction.rs
@@ -119,6 +119,7 @@ mod tests {
             movement: na::Vector3::x(),
             jump: false,
             no_clip: true,
+            debug_spawn_blinker: false,
             block_update: None,
         };
 
diff --git a/client/src/sim.rs b/client/src/sim.rs
index 983e818e..e39531ba 100644
--- a/client/src/sim.rs
+++ b/client/src/sim.rs
@@ -15,7 +15,7 @@ use common::{
     graph_ray_casting,
     node::{populate_fresh_nodes, ChunkId, VoxelData},
     proto::{
-        self, BlockUpdate, Character, CharacterInput, CharacterState, Command, Component,
+        self, Blinker, BlockUpdate, Character, CharacterInput, CharacterState, Command, Component,
         Inventory, Position,
     },
     sanitize_motion_input,
@@ -64,6 +64,7 @@ pub struct Sim {
     no_clip: bool,
     /// Whether no_clip will be toggled next step
     toggle_no_clip: bool,
+    debug_spawn_blinker: bool,
     /// Whether the current step starts with a jump
     is_jumping: bool,
     /// Whether the jump button has been pressed since the last step
@@ -101,6 +102,7 @@ impl Sim {
             average_movement_input: na::zero(),
             no_clip: true,
             toggle_no_clip: false,
+            debug_spawn_blinker: false,
             is_jumping: false,
             jump_pressed: false,
             jump_held: false,
@@ -145,6 +147,11 @@ impl Sim {
         self.toggle_no_clip = true;
     }
 
+    pub fn debug_spawn_blinker(&mut self) {
+        // Note: the blinker currently does nothing but update internal state
+        self.debug_spawn_blinker = true;
+    }
+
     pub fn set_jump_held(&mut self, jump_held: bool) {
         self.jump_held = jump_held;
         self.jump_pressed = jump_held || self.jump_pressed;
@@ -287,6 +294,9 @@ impl Sim {
                 for &(id, ref new_state) in &msg.character_states {
                     self.update_character_state(id, new_state);
                 }
+                for &(id, ref new_blinker) in &msg.blinker_states {
+                    self.update_blinker_state(id, new_blinker);
+                }
                 self.reconcile_prediction(msg.latest_input);
             }
         }
@@ -322,6 +332,20 @@ impl Sim {
         }
     }
 
+    fn update_blinker_state(&mut self, id: EntityId, new_blinker: &Blinker) {
+        match self.entity_ids.get(&id) {
+            None => debug!(%id, "blinker state update for unknown entity"),
+            Some(&entity) => match self.world.get::<&mut Blinker>(entity) {
+                Ok(mut blinker) => {
+                    *blinker = new_blinker.clone();
+                }
+                Err(e) => {
+                    error!(%id, "blinker state update error: {}", e)
+                }
+            },
+        }
+    }
+
     fn reconcile_prediction(&mut self, latest_input: u16) {
         let id = self.local_character_id;
         let Some(&entity) = self.entity_ids.get(&id) else {
@@ -424,6 +448,9 @@ impl Sim {
                     node = Some(x.node);
                     builder.add(x);
                 }
+                Blinker(x) => {
+                    builder.add(x);
+                }
                 Inventory(x) => {
                     builder.add(x);
                 }
@@ -455,6 +482,7 @@ impl Sim {
             movement: sanitize_motion_input(orientation * self.average_movement_input),
             jump: self.is_jumping,
             no_clip: self.no_clip,
+            debug_spawn_blinker: self.debug_spawn_blinker,
             block_update: self.get_local_character_block_update(),
         };
         let generation = self
@@ -467,6 +495,7 @@ impl Sim {
             character_input,
             orientation: self.local_character_controller.orientation(),
         });
+        self.debug_spawn_blinker = false;
     }
 
     fn update_view_position(&mut self) {
@@ -488,6 +517,7 @@ impl Sim {
                 / (self.since_input_sent.as_secs_f32() / self.cfg.step_interval.as_secs_f32()),
             jump: self.is_jumping,
             no_clip: self.no_clip,
+            debug_spawn_blinker: self.debug_spawn_blinker,
             block_update: None,
         };
         character_controller::run_character_step(
diff --git a/common/src/proto.rs b/common/src/proto.rs
index b8db0c82..719e77f4 100644
--- a/common/src/proto.rs
+++ b/common/src/proto.rs
@@ -38,6 +38,7 @@ pub struct StateDelta {
     pub latest_input: u16,
     pub positions: Vec<(EntityId, Position)>,
     pub character_states: Vec<(EntityId, CharacterState)>,
+    pub blinker_states: Vec<(EntityId, Blinker)>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -72,6 +73,7 @@ pub struct CharacterInput {
     pub movement: na::Vector3<f32>,
     pub jump: bool,
     pub no_clip: bool,
+    pub debug_spawn_blinker: bool,
     pub block_update: Option<BlockUpdate>,
 }
 
@@ -93,6 +95,7 @@ pub struct SerializedVoxelData {
 pub enum Component {
     Character(Character),
     Position(Position),
+    Blinker(Blinker),
     Material(Material),
     Inventory(Inventory),
 }
@@ -110,6 +113,11 @@ pub struct Character {
     pub state: CharacterState,
 }
 
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct Blinker {
+    pub on: bool,
+}
+
 #[derive(Debug, Serialize, Deserialize, Clone)]
 pub struct Inventory {
     pub contents: Vec<EntityId>,
diff --git a/server/src/sim.rs b/server/src/sim.rs
index dac719b4..42f33e3b 100644
--- a/server/src/sim.rs
+++ b/server/src/sim.rs
@@ -19,8 +19,8 @@ use common::{
     math,
     node::{populate_fresh_nodes, Chunk},
     proto::{
-        Character, CharacterInput, CharacterState, ClientHello, Command, Component, FreshNode,
-        Position, Spawns, StateDelta,
+        Blinker, Character, CharacterInput, CharacterState, ClientHello, Command, Component,
+        FreshNode, Position, Spawns, StateDelta,
     },
     traversal::{ensure_nearby, nearby_nodes},
     worldgen::ChunkParams,
@@ -203,6 +203,7 @@ impl Sim {
             movement: na::Vector3::zeros(),
             jump: false,
             no_clip: true,
+            debug_spawn_blinker: false,
             block_update: None,
         };
         self.spawn((position, character, inventory, initial_input))
@@ -289,6 +290,16 @@ impl Sim {
         let span = error_span!("step", step = self.step);
         let _guard = span.enter();
 
+        for (_entity, blinker) in self.world.query::<&mut Blinker>().iter() {
+            blinker.on = !blinker.on;
+
+            if blinker.on {
+                tracing::info!("Blinked ON");
+            } else {
+                tracing::info!("Blinked OFF");
+            }
+        }
+
         // Extend graph structure
         for (_, (position, _)) in self.world.query::<(&mut Position, &mut Character)>().iter() {
             ensure_nearby(&mut self.graph, position, self.cfg.view_distance);
@@ -341,6 +352,7 @@ impl Sim {
             }
         }
 
+        let mut pending_blinker_spawns: Vec<(Position, Blinker)> = Vec::new();
         let mut pending_block_updates: Vec<(Entity, BlockUpdate)> = vec![];
 
         // Simulate
@@ -350,6 +362,10 @@ impl Sim {
             .iter()
         {
             let prev_node = position.node;
+            if input.debug_spawn_blinker {
+                let blinker: Blinker = Blinker { on: false };
+                pending_blinker_spawns.push((*position, blinker));
+            }
             character_controller::run_character_step(
                 &self.cfg,
                 &self.graph,
@@ -370,6 +386,10 @@ impl Sim {
             self.dirty_nodes.insert(position.node);
         }
 
+        for (position, blinker) in pending_blinker_spawns {
+            self.spawn((position, blinker));
+        }
+
         for (entity, block_update) in pending_block_updates {
             let id = *self.world.get::<&EntityId>(entity).unwrap();
             self.attempt_block_update(id, block_update);
@@ -397,6 +417,12 @@ impl Sim {
                 .iter()
                 .map(|(_, (&id, ch))| (id, ch.state.clone()))
                 .collect(),
+            blinker_states: self
+                .world
+                .query::<(&EntityId, &Blinker)>()
+                .iter()
+                .map(|(_, (&id, blinker))| (id, blinker.clone()))
+                .collect(),
         };
 
         self.step += 1;
@@ -495,6 +521,9 @@ fn dump_entity(world: &hecs::World, entity: Entity) -> Vec<Component> {
     if let Ok(x) = world.get::<&Character>(entity) {
         components.push(Component::Character((*x).clone()));
     }
+    if let Ok(x) = world.get::<&Blinker>(entity) {
+        components.push(Component::Blinker((*x).clone()));
+    }
     if let Ok(x) = world.get::<&Inventory>(entity) {
         components.push(Component::Inventory((*x).clone()));
     }