diff --git a/src/ai/energy_system.rs b/src/ai/energy_system.rs
new file mode 100644
index 0000000..68238dd
--- /dev/null
+++ b/src/ai/energy_system.rs
@@ -0,0 +1,51 @@
+use crate::{Energy, Position, RunState, TakingTurn};
+use rltk::prelude::*;
+use specs::prelude::*;
+
+pub struct EnergySystem {}
+
+const NORMAL_SPEED: i32 = 12;
+const TURN_COST: i32 = NORMAL_SPEED * 4;
+
+impl<'a> System<'a> for EnergySystem {
+    #[allow(clippy::type_complexity)]
+    type SystemData = (
+        WriteStorage<'a, Energy>,
+        ReadStorage<'a, Position>,
+        WriteStorage<'a, TakingTurn>,
+        Entities<'a>,
+        WriteExpect<'a, RandomNumberGenerator>,
+        WriteExpect<'a, RunState>,
+        ReadExpect<'a, Entity>,
+    );
+
+    fn run(&mut self, data: Self::SystemData) {
+        let (mut energies, positions, mut turns, entities, mut rng, mut runstate, player) = data;
+
+        if *runstate != RunState::MonsterTurn {
+            return;
+        }
+
+        turns.clear();
+
+        for (entity, energy, _pos) in (&entities, &mut energies, &positions).join() {
+            let mut energy_potential: i32 = energy.speed;
+            while energy_potential >= NORMAL_SPEED {
+                energy_potential -= NORMAL_SPEED;
+                energy.current += NORMAL_SPEED;
+            }
+            if energy_potential > 0 {
+                if rng.roll_dice(1, NORMAL_SPEED) <= energy_potential {
+                    energy.current += NORMAL_SPEED;
+                }
+            }
+            if energy.current >= TURN_COST {
+                turns.insert(entity, TakingTurn {}).expect("Unable to insert turn.");
+                energy.current -= TURN_COST;
+                if entity == *player {
+                    *runstate = RunState::AwaitingInput;
+                }
+            }
+        }
+    }
+}
diff --git a/src/ai/mod.rs b/src/ai/mod.rs
new file mode 100644
index 0000000..efa6f52
--- /dev/null
+++ b/src/ai/mod.rs
@@ -0,0 +1,2 @@
+mod energy_system;
+pub use energy_system::EnergySystem;
diff --git a/src/components.rs b/src/components.rs
index 00d17c0..3ff6930 100644
--- a/src/components.rs
+++ b/src/components.rs
@@ -46,6 +46,15 @@ pub struct LootTable {
     pub chance: f32,
 }
 
+#[derive(Component, Debug, Serialize, Deserialize, Clone)]
+pub struct Energy {
+    pub current: i32,
+    pub speed: i32,
+}
+
+#[derive(Component, Debug, Serialize, Deserialize, Clone)]
+pub struct TakingTurn {}
+
 #[derive(Component, Debug, Serialize, Deserialize, Clone)]
 pub struct Bystander {}
 
diff --git a/src/main.rs b/src/main.rs
index a2e90d4..57ab534 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -35,6 +35,7 @@ mod inventory_system;
 use inventory_system::*;
 mod particle_system;
 use particle_system::{ParticleBuilder, DEFAULT_PARTICLE_LIFETIME, LONG_PARTICLE_LIFETIME};
+mod ai;
 mod gamesystem;
 mod random_table;
 mod rex_assets;
@@ -533,6 +534,8 @@ fn main() -> rltk::BError {
     gs.ecs.register::<Item>();
     gs.ecs.register::<GrantsXP>();
     gs.ecs.register::<LootTable>();
+    gs.ecs.register::<Energy>();
+    gs.ecs.register::<TakingTurn>();
     gs.ecs.register::<Equippable>();
     gs.ecs.register::<Equipped>();
     gs.ecs.register::<MeleeWeapon>();
diff --git a/src/raws/mob_structs.rs b/src/raws/mob_structs.rs
index 656e69c..68f0ab3 100644
--- a/src/raws/mob_structs.rs
+++ b/src/raws/mob_structs.rs
@@ -10,6 +10,7 @@ pub struct Mob {
     pub flags: Option<Vec<String>>,
     pub level: Option<i32>,
     pub bac: Option<i32>,
+    pub speed: Option<i32>,
     pub attacks: Option<Vec<NaturalAttack>>,
     pub attributes: Option<MobAttributes>,
     pub skills: Option<HashMap<String, i32>>,
diff --git a/src/raws/rawmaster.rs b/src/raws/rawmaster.rs
index 6892012..87b3d71 100644
--- a/src/raws/rawmaster.rs
+++ b/src/raws/rawmaster.rs
@@ -276,6 +276,9 @@ pub fn spawn_named_mob(
         }
         eb = eb.with(attr);
 
+        let speed = if mob_template.speed.is_some() { mob_template.speed.unwrap() } else { 12 };
+        eb = eb.with(Energy { current: 0, speed: speed });
+
         let base_mob_level = if mob_template.level.is_some() { mob_template.level.unwrap() } else { 0 };
         let mut mob_level = base_mob_level;
         // If the level difficulty is smaller than the mob's base level, subtract 1;
@@ -347,8 +350,11 @@ pub fn spawn_named_mob(
         }
 
         xp_value += mob_level * mob_level;
-        // if speed > 18, +5
-        // if speed > 12, +3
+        if speed > 18 {
+            xp_value += 5;
+        } else if speed > 12 {
+            xp_value += 3;
+        }
         if mob_bac < 0 {
             xp_value += 14 + 2 * mob_bac;
         } else if mob_bac == 0 {
diff --git a/src/saveload_system.rs b/src/saveload_system.rs
index a53e3da..bf9f90a 100644
--- a/src/saveload_system.rs
+++ b/src/saveload_system.rs
@@ -59,6 +59,7 @@ pub fn save_game(ecs: &mut World) {
             Destructible,
             Digger,
             Door,
+            Energy,
             EntityMoved,
             EntryTrigger,
             Equippable,
@@ -90,6 +91,7 @@ pub fn save_game(ecs: &mut World) {
             SingleActivation,
             Skills,
             SufferDamage,
+            TakingTurn,
             Telepath,
             Viewshed,
             Wand,
@@ -163,6 +165,7 @@ pub fn load_game(ecs: &mut World) {
             Destructible,
             Digger,
             Door,
+            Energy,
             EntityMoved,
             EntryTrigger,
             Equippable,
@@ -194,6 +197,7 @@ pub fn load_game(ecs: &mut World) {
             SingleActivation,
             Skills,
             SufferDamage,
+            TakingTurn,
             Telepath,
             Viewshed,
             Wand,
diff --git a/src/spawner.rs b/src/spawner.rs
index 67dd1c9..49fb102 100644
--- a/src/spawner.rs
+++ b/src/spawner.rs
@@ -1,5 +1,5 @@
 use super::{
-    gamesystem, gamesystem::attr_bonus, random_table::RandomTable, raws, Attribute, Attributes, HungerClock,
+    gamesystem, gamesystem::attr_bonus, random_table::RandomTable, raws, Attribute, Attributes, Energy, HungerClock,
     HungerState, Map, Name, Player, Pool, Pools, Position, Rect, Renderable, SerializeMe, Skill, Skills, TileType,
     Viewshed,
 };
@@ -54,6 +54,7 @@ pub fn player(ecs: &mut World, player_x: i32, player_y: i32) -> Entity {
             bac: 10,
         })
         .with(skills)
+        .with(Energy { current: 0, speed: 12 })
         .marked::<SimpleMarker<SerializeMe>>()
         .build();