diff --git a/src/damage_system.rs b/src/damage_system.rs
index f7ab9ba..e58755f 100644
--- a/src/damage_system.rs
+++ b/src/damage_system.rs
@@ -1,16 +1,27 @@
-use super::{gamelog::GameLog, CombatStats, Name, Player, SufferDamage};
+use super::{gamelog::GameLog, CombatStats, Entities, Map, Name, Player, Position, SufferDamage};
 use specs::prelude::*;
 
 pub struct DamageSystem {}
 
 impl<'a> System<'a> for DamageSystem {
-    type SystemData = (WriteStorage<'a, CombatStats>, WriteStorage<'a, SufferDamage>);
+    type SystemData = (
+        WriteStorage<'a, CombatStats>,
+        WriteStorage<'a, SufferDamage>,
+        WriteExpect<'a, Map>,
+        ReadStorage<'a, Position>,
+        Entities<'a>,
+    );
 
     fn run(&mut self, data: Self::SystemData) {
-        let (mut stats, mut damage) = data;
+        let (mut stats, mut damage, mut map, positions, entities) = data;
 
-        for (mut stats, damage) in (&mut stats, &damage).join() {
+        for (entity, mut stats, damage) in (&entities, &mut stats, &damage).join() {
             stats.hp -= damage.amount.iter().sum::<i32>();
+            let pos = positions.get(entity);
+            if let Some(pos) = pos {
+                let idx = map.xy_idx(pos.x, pos.y);
+                map.bloodstains.insert(idx);
+            }
         }
 
         damage.clear();
diff --git a/src/main.rs b/src/main.rs
index 6ae8a8e..9d2af59 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,4 @@
-use rltk::{GameState, Point, Rltk};
+use rltk::{GameState, Point, Rltk, RGB};
 use specs::prelude::*;
 
 mod components;
@@ -82,8 +82,12 @@ impl GameState for State {
             data.sort_by(|&a, &b| b.1.render_order.cmp(&a.1.render_order));
             for (pos, render) in data.iter() {
                 let idx = map.xy_idx(pos.x, pos.y);
+                let mut bg = render.bg;
+                if map.bloodstains.contains(&idx) {
+                    bg = RGB::from_f32(0.4, 0., 0.);
+                }
                 if map.visible_tiles[idx] {
-                    ctx.set(pos.x, pos.y, render.fg, render.bg, render.glyph);
+                    ctx.set(pos.x, pos.y, render.fg, bg, render.glyph);
                 }
             }
             gui::draw_ui(&self.ecs, ctx);
diff --git a/src/map.rs b/src/map.rs
index fc719d8..2bfb6e3 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -2,6 +2,7 @@ use super::Rect;
 use rltk::{Algorithm2D, BaseMap, Point, RandomNumberGenerator, Rltk, RGB};
 use specs::prelude::*;
 use std::cmp::{max, min};
+use std::collections::HashSet;
 
 #[derive(PartialEq, Copy, Clone)]
 pub enum TileType {
@@ -23,6 +24,7 @@ pub struct Map {
     pub visible_tiles: Vec<bool>,
     pub blocked: Vec<bool>,
     pub tile_content: Vec<Vec<Entity>>,
+    pub bloodstains: HashSet<usize>,
 }
 
 impl Map {
@@ -89,6 +91,7 @@ impl Map {
             visible_tiles: vec![false; MAPCOUNT],
             blocked: vec![false; MAPCOUNT],
             tile_content: vec![Vec::new(); MAPCOUNT],
+            bloodstains: HashSet::new(),
         };
 
         const MAX_ROOMS: i32 = 30;
@@ -198,6 +201,7 @@ pub fn draw_map(ecs: &World, ctx: &mut Rltk) {
         if map.revealed_tiles[idx] {
             let glyph;
             let mut fg;
+            let mut bg = RGB::from_f32(0., 0., 0.);
             match tile {
                 TileType::Floor => {
                     glyph = rltk::to_cp437('.');
@@ -208,10 +212,14 @@ pub fn draw_map(ecs: &World, ctx: &mut Rltk) {
                     fg = RGB::from_f32(0.0, 1.0, 0.0);
                 }
             }
+            if map.bloodstains.contains(&idx) {
+                bg = RGB::from_f32(0.4, 0., 0.);
+            }
             if !map.visible_tiles[idx] {
                 fg = fg.to_greyscale();
+                bg = bg.desaturate();
             }
-            ctx.set(x, y, fg, RGB::from_f32(0.0, 0.0, 0.0), glyph);
+            ctx.set(x, y, fg, bg, glyph);
         }
 
         // Move the coordinates