diff --git a/src/game.rs b/src/game.rs
index 34495d4..1fadfef 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -27,6 +27,7 @@ pub struct Game {
     /// the levels of the game
     levels: Vec<Level>,
     pub messages: Vec<String>,
+    use_fog_of_war: bool,
 }
 
 impl Game {
@@ -39,6 +40,7 @@ impl Game {
             player: p,
             levels: v,
             messages: Vec::with_capacity(10),
+            use_fog_of_war: true,
         };
         let start = {
             g.get_level(0).start
@@ -74,6 +76,8 @@ impl Game {
     pub fn get_player(&self) -> &Player {
         &self.player
     }
+    pub fn toggle_fog_of_war(&mut self) { self.use_fog_of_war = !self.use_fog_of_war; }
+    pub fn uses_fog_of_war(&self) -> bool { self.use_fog_of_war }
     pub fn get_mutable_player(&mut self) -> &mut Player {
         &mut self.player
     }
@@ -105,7 +109,7 @@ impl Game {
         let new_y: i16 = player_pos.get_y() as i16 + dy;
         let player_level = player_pos.get_level();
         let level = &mut self.levels[player_level];
-        level.get_element(new_x, new_y).0
+        level.get_element(new_x, new_y, self.use_fog_of_war).0
     }
 
     /// move the game's player into the given direction. If on the target field there is a stair,
@@ -155,7 +159,7 @@ impl Game {
         let player_pos = &self.player.get_immutable_position();
         let player_level = player_pos.get_level();
         let level = &mut self.levels[player_level];
-        let (_, m, _) = level.get_element(player_pos.get_x() as i16, player_pos.get_y() as i16);
+        let (_, m, _) = level.get_element(player_pos.get_x() as i16, player_pos.get_y() as i16, true);
         match m {
             None => {}
             Some(m) => {
@@ -186,7 +190,7 @@ impl Game {
         let player_pos = &self.player.get_immutable_position();
         let player_level = player_pos.get_level();
         let level = &mut self.levels[player_level];
-        let (_, _, a) = level.get_element(player_pos.get_x() as i16, player_pos.get_y() as i16);
+        let (_, _, a) = level.get_element(player_pos.get_x() as i16, player_pos.get_y() as i16, true);
         match a {
             None => {}
             Some(a) => {
diff --git a/src/level.rs b/src/level.rs
index 3f07f95..ba8f056 100644
--- a/src/level.rs
+++ b/src/level.rs
@@ -38,7 +38,7 @@ pub struct Level {
 }
 
 impl Level {
-    pub fn get_element(&mut self, x: i16, y: i16) -> (Option<StructureElement>, Option<&mut Box<(dyn Monster + 'static)>>, Option<&mut Box<(dyn Artifact + 'static)>>) {
+    pub fn get_element(&mut self, x: i16, y: i16, use_fog_of_war: bool) -> (Option<StructureElement>, Option<&mut Box<(dyn Monster + 'static)>>, Option<&mut Box<(dyn Artifact + 'static)>>) {
         if x < 0 || y < 0 {
             return (None, None, None);
         }
@@ -47,7 +47,7 @@ impl Level {
         if x >= LEVEL_WIDTH || y >= LEVEL_HEIGHT {
             return (None, None, None);
         }
-        if !self.discovered[x][y] {
+        if use_fog_of_war && !self.discovered[x][y] {
             return (Some(StructureElement::Unknown), None, None);
         }
         let search_pos = &Position::new(self.level, x, y);
@@ -239,23 +239,23 @@ impl Level {
 #[test]
 fn test_get_element() {
     let mut l = Level::new(0);
-    assert_eq!(l.get_element(-1, -1).0, None);
-    assert_eq!(l.get_element(0, 0).0.unwrap(), StructureElement::Unknown);
-    assert_eq!(l.get_element(LEVEL_WIDTH as i16 - 1, LEVEL_HEIGHT as i16 - 1).0.unwrap(), StructureElement::Unknown);
-    assert_eq!(l.get_element(LEVEL_WIDTH as i16, LEVEL_HEIGHT as i16).0, None);
+    assert_eq!(l.get_element(-1, -1, true).0, None);
+    assert_eq!(l.get_element(0, 0, true).0.unwrap(), StructureElement::Unknown);
+    assert_eq!(l.get_element(LEVEL_WIDTH as i16 - 1, LEVEL_HEIGHT as i16 - 1, true).0.unwrap(), StructureElement::Unknown);
+    assert_eq!(l.get_element(LEVEL_WIDTH as i16, LEVEL_HEIGHT as i16, true).0, None);
 }
 
 #[test]
 fn test_discover_get_element() {
     let mut l = Level::new(0);
-    assert_eq!(l.get_element(10, 10).0.unwrap(), StructureElement::Unknown);
+    assert_eq!(l.get_element(10, 10, true).0.unwrap(), StructureElement::Unknown);
     let p = Position::new(0, 10, 10);
     l.discover(&p);
-    assert_eq!(l.get_element(10, 10).0.unwrap(), StructureElement::Floor);
-    assert_eq!(l.get_element(9, 10).0.unwrap(), StructureElement::Floor);
-    assert_eq!(l.get_element(10, 9).0.unwrap(), StructureElement::Floor);
-    assert_eq!(l.get_element(11, 10).0.unwrap(), StructureElement::Floor);
-    assert_eq!(l.get_element(10, 11).0.unwrap(), StructureElement::Floor);
+    assert_eq!(l.get_element(10, 10, true).0.unwrap(), StructureElement::Floor);
+    assert_eq!(l.get_element(9, 10, true).0.unwrap(), StructureElement::Floor);
+    assert_eq!(l.get_element(10, 9, true).0.unwrap(), StructureElement::Floor);
+    assert_eq!(l.get_element(11, 10, true).0.unwrap(), StructureElement::Floor);
+    assert_eq!(l.get_element(10, 11, true).0.unwrap(), StructureElement::Floor);
 }
 
 #[test]
@@ -296,20 +296,20 @@ fn test_discover_get_monster() {
     let mut l = Level::new(0);
     let p = Position::new(0, 10, 10);
     l.discover(&p);
-    assert_eq!(l.get_element(10, 10).0.unwrap(), StructureElement::Floor);
-    assert!(l.get_element(10, 10).1.is_none());
+    assert_eq!(l.get_element(10, 10, true).0.unwrap(), StructureElement::Floor);
+    assert!(l.get_element(10, 10, true).1.is_none());
 
     let m = Rat::new_with_position(Position::new(0, 10, 10));
     assert_eq!(l.add_monster(m), Ok(()));
 
-    let elem = l.get_element(10, 10);
+    let elem = l.get_element(10, 10, true);
     assert_eq!(elem.0.unwrap(), StructureElement::Floor);
     assert!(elem.1.is_some());
     let m = elem.1.unwrap();
     assert_eq!(m.get_life(), 3);
 
     m.decrease_life(3);
-    assert_eq!(l.get_element(10, 10).1.unwrap().get_life(), 0);
+    assert_eq!(l.get_element(10, 10, true).1.unwrap().get_life(), 0);
 }
 
 #[test]
@@ -317,13 +317,13 @@ fn test_discover_get_artifact() {
     let mut l = Level::new(0);
     let p = Position::new(0, 10, 10);
     l.discover(&p);
-    assert_eq!(l.get_element(10, 10).0.unwrap(), StructureElement::Floor);
-    assert!(l.get_element(10, 10).2.is_none());
+    assert_eq!(l.get_element(10, 10, true).0.unwrap(), StructureElement::Floor);
+    assert!(l.get_element(10, 10, true).2.is_none());
 
     let a = Chest::new(Position::new(0, 10, 10));
     assert_eq!(l.add_artifact(a), Ok(()));
 
-    let elem = l.get_element(10, 10);
+    let elem = l.get_element(10, 10, true);
     assert_eq!(elem.0.unwrap(), StructureElement::Floor);
     assert!(elem.2.is_some());
 }
@@ -337,12 +337,12 @@ fn test_discover_get_monster_can_move() {
     let m = Rat::new_with_position(Position::new(0, 10, 10));
     l.add_monster(m).expect("Panic because of");
 
-    let m = l.get_element(10, 10).1.unwrap();
+    let m = l.get_element(10, 10, true).1.unwrap();
     m.get_position().change(1, 1);
 
-    let m = l.get_element(10, 10).1;
+    let m = l.get_element(10, 10, true).1;
     assert!(m.is_none());
-    let m = l.get_element(11, 11).1;
+    let m = l.get_element(11, 11, true).1;
     assert!(m.is_some());
     assert_eq!(m.unwrap().get_life(), 3);
 }
diff --git a/src/level_widget.rs b/src/level_widget.rs
index 5154a71..0a861f6 100644
--- a/src/level_widget.rs
+++ b/src/level_widget.rs
@@ -9,9 +9,16 @@ use crate::position::HasPosition;
 
 const FG_BROWN: Color = Color::Rgb(186, 74, 0);
 
-pub struct LevelWidget {}
+pub struct LevelWidget {
+    use_fog_of_war: bool,
+}
 
 impl LevelWidget {
+    pub fn new(use_fog_of_war: bool) -> Self {
+        LevelWidget {
+            use_fog_of_war
+        }
+    }
     fn set_cell(&self, buf: &mut Buffer, x: u16, y: u16, symbol: &str, fg: Color, bg: Color) {
         buf.
             get_mut(x, y).
@@ -39,7 +46,7 @@ impl StatefulWidget for LevelWidget {
                     let level = state.get_mutable_level(player_level);
                     let level_x = (x - al) as i16;
                     let level_y = (y - at) as i16;
-                    match level.get_element(level_x, level_y) {
+                    match level.get_element(level_x, level_y, self.use_fog_of_war) {
                         (Some(structure_element), None, None) => {
                             match structure_element {
                                 StructureElement::Start => {
diff --git a/src/main.rs b/src/main.rs
index 88e0d48..af17b53 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -83,7 +83,7 @@ fn main() -> Result<()> {
                 width: level::LEVEL_WIDTH as u16,
                 height: level::LEVEL_HEIGHT as u16,
             };
-            frame.render_stateful_widget(LevelWidget {}, map_area, &mut game);
+            frame.render_stateful_widget(LevelWidget::new(game.uses_fog_of_war()), map_area, &mut game);
 
             let stats_area = Rect {
                 x: area.x + 50,
@@ -137,6 +137,13 @@ fn main() -> Result<()> {
                 if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('v') {
                     game.messages.insert(0, format!("You are playing version '{}'.", env!("GIT_HASH")).to_string());
                 }
+                // disabling the d key (disable fog of war) in release builds!
+                #[cfg(debug_assertions)]
+                if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('d') {
+                    game.messages.insert(0, "toggle fog of war!".to_string());
+                    game.toggle_fog_of_war();
+                }
+
                 if key.kind == KeyEventKind::Press && key.code == KeyCode::Char('q') {
                     break;
                 }