diff --git a/justfile b/justfile
new file mode 100644
index 0000000..8ae16d2
--- /dev/null
+++ b/justfile
@@ -0,0 +1,8 @@
+gen year day:
+	cargo run -- {{year}} {{day}}
+
+run year day:
+	cargo run --package y{{year}} --bin d{{day}}
+
+test year day *part='1':
+	cargo test --package y{{year}} days::d{{day}}::tests::part{{part}} -- --nocapture
diff --git a/y2015/resources/22_input.txt b/y2015/resources/22_input.txt
new file mode 100644
index 0000000..db93bd0
--- /dev/null
+++ b/y2015/resources/22_input.txt
@@ -0,0 +1,2 @@
+Hit Points: 71
+Damage: 10
diff --git a/y2015/src/bin/d22.rs b/y2015/src/bin/d22.rs
new file mode 100644
index 0000000..7b23363
--- /dev/null
+++ b/y2015/src/bin/d22.rs
@@ -0,0 +1,20 @@
+use std::fs;
+
+use y2015::days::d22;
+
+fn main() {
+    part1();
+    part2();
+}
+
+fn part1() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/22_input.txt")).unwrap();
+    println!("{}", d22::process_part1(&content));
+}
+
+fn part2() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/22_input.txt")).unwrap();
+    println!("{}", d22::process_part2(&content));
+}
diff --git a/y2015/src/days/d21.rs b/y2015/src/days/d21.rs
index ea8583c..de8f310 100644
--- a/y2015/src/days/d21.rs
+++ b/y2015/src/days/d21.rs
@@ -267,24 +267,3 @@ impl Character {
         self.items_value += item.cost;
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    const INPUT: &str = "Hit Points: 12
-Damage: 7
-Armor: 2";
-
-    #[test]
-    fn part1() {
-        let result = process_part1(INPUT);
-        assert_eq!(result, 0);
-    }
-
-    #[test]
-    fn part2() {
-        let result = process_part2(INPUT);
-        assert_eq!(result, 0);
-    }
-}
diff --git a/y2015/src/days/d22.rs b/y2015/src/days/d22.rs
new file mode 100644
index 0000000..d5b904c
--- /dev/null
+++ b/y2015/src/days/d22.rs
@@ -0,0 +1,319 @@
+pub fn process_part1(input: &str) -> u32 {
+    let mut boss = Character::default();
+    input.lines().for_each(|line| {
+        let (attribute, value) = line.split_once(": ").unwrap();
+        if attribute == "Hit Points" {
+            boss.hp = value.parse::<u32>().unwrap();
+        } else if attribute == "Damage" {
+            boss.damage = value.parse::<u32>().unwrap();
+        }
+    });
+    let player = Character {
+        hp: 50,
+        mana: 500,
+        ..Default::default()
+    };
+    let mut used_mana = Vec::new();
+    for spell in Spell::get_all() {
+        used_mana.push(round(player.clone(), boss.clone(), spell, 0));
+    }
+    let mut smallest = u32::MAX;
+    for state in used_mana {
+        if state.get_value() < smallest {
+            smallest = state.get_value();
+        }
+    }
+    smallest
+}
+
+pub fn process_part2(input: &str) -> u32 {
+    0
+}
+
+fn round(mut player: Character, mut boss: Character, spell: Spell, spent_so_far: u32) -> State {
+    // Player turn
+    for effect in player.status_effects.iter_mut() {
+        if effect.name == SpellID::Recharge {
+            player.mana += effect.mana;
+        }
+        effect.duration -= 1;
+        if effect.duration > 0 && effect.name == SpellID::Shield {
+            player.armor = effect.armor;
+        } else if effect.name == SpellID::Shield {
+            player.armor = 0;
+        }
+    }
+    for effect in boss.status_effects.iter_mut() {
+        boss.hp = boss.hp.saturating_sub(effect.damage);
+        effect.duration -= 1;
+    }
+    boss.status_effects = boss
+        .status_effects
+        .into_iter()
+        .filter(|&effect| effect.duration > 0)
+        .collect::<Vec<Spell>>();
+    player.status_effects = player
+        .status_effects
+        .into_iter()
+        .filter(|&effect| effect.duration > 0)
+        .collect::<Vec<Spell>>();
+    let used_mana = spell.cost + spent_so_far;
+    let mut dmg = 0;
+    match spell.name {
+        SpellID::MagicMissile => {
+            player.mana = player.mana.saturating_sub(spell.cost);
+            dmg = spell.damage;
+        }
+        SpellID::Drain => {
+            player.mana = player.mana.saturating_sub(spell.cost);
+            dmg = spell.damage;
+            player.hp += spell.hp;
+        }
+        SpellID::Shield => {
+            player.mana = player.mana.saturating_sub(spell.cost);
+            player.status_effects.push(spell);
+            player.armor = spell.armor;
+        }
+        SpellID::Poison => {
+            player.mana = player.mana.saturating_sub(spell.cost);
+            boss.status_effects.push(spell);
+        }
+        SpellID::Recharge => {
+            player.mana = player.mana.saturating_sub(spell.cost);
+            player.status_effects.push(spell);
+        }
+    }
+    boss.hp = boss.hp.saturating_sub(dmg);
+    if boss.hp == 0 {
+        return State::Win(used_mana);
+    }
+    if player.mana == 0 {
+        return State::Loss(0);
+    }
+
+    // Boss turn
+    for effect in player.status_effects.iter_mut() {
+        if effect.name == SpellID::Recharge {
+            player.mana += effect.mana;
+        }
+        effect.duration -= 1;
+        if effect.duration > 0 && effect.name == SpellID::Shield {
+            player.armor = effect.armor;
+        } else if effect.name == SpellID::Shield {
+            player.armor = 0;
+        }
+    }
+    player.status_effects = player
+        .status_effects
+        .into_iter()
+        .filter(|&effect| effect.duration > 0)
+        .collect::<Vec<Spell>>();
+    for effect in boss.status_effects.iter_mut() {
+        boss.hp = boss.hp.saturating_sub(effect.damage);
+        effect.duration -= 1;
+    }
+    if boss.hp == 0 {
+        return State::Win(used_mana);
+    }
+    boss.status_effects = boss
+        .status_effects
+        .into_iter()
+        .filter(|&effect| effect.duration > 0)
+        .collect::<Vec<Spell>>();
+    let dmg = boss.hit_damage(&player);
+    player.hp = player.hp.saturating_sub(dmg);
+
+    if player.hp == 0 {
+        return State::Loss(0);
+    }
+
+    // next round
+    let mut smallest_used_mana = State::Playing(u32::MAX);
+    for spell in Spell::get_all() {
+        let next_state = round(player.clone(), boss.clone(), spell, used_mana);
+        match next_state {
+            State::Playing(mana) => {
+                if mana < smallest_used_mana.get_value() {
+                    smallest_used_mana = State::Playing(mana);
+                }
+            }
+            State::Win(mana) => {
+                if mana < smallest_used_mana.get_value() {
+                    smallest_used_mana = State::Win(mana);
+                }
+            }
+            State::Loss(_) => {}
+        };
+    }
+    smallest_used_mana
+}
+
+#[derive(Debug)]
+enum State {
+    Playing(u32),
+    Win(u32),
+    Loss(u32),
+}
+
+impl State {
+    fn get_value(&self) -> u32 {
+        match self {
+            State::Playing(value) => *value,
+            State::Win(value) => *value,
+            State::Loss(value) => *value,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum SpellID {
+    MagicMissile,
+    Drain,
+    Shield,
+    Poison,
+    Recharge,
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Spell {
+    name: SpellID,
+    hp: u32,
+    damage: u32,
+    mana: u32,
+    armor: u32,
+    duration: u32,
+    cost: u32,
+}
+
+impl Spell {
+    fn get_all() -> Vec<Spell> {
+        vec![
+            Spell {
+                name: SpellID::MagicMissile,
+                hp: 0,
+                damage: 4,
+                mana: 0,
+                armor: 0,
+                duration: 0,
+                cost: 53,
+            },
+            Spell {
+                name: SpellID::Drain,
+                hp: 2,
+                damage: 2,
+                mana: 0,
+                armor: 0,
+                duration: 0,
+                cost: 73,
+            },
+            Spell {
+                name: SpellID::Shield,
+                hp: 0,
+                damage: 0,
+                mana: 0,
+                armor: 7,
+                duration: 6,
+                cost: 113,
+            },
+            Spell {
+                name: SpellID::Poison,
+                hp: 0,
+                damage: 3,
+                mana: 0,
+                armor: 0,
+                duration: 6,
+                cost: 173,
+            },
+            Spell {
+                name: SpellID::Recharge,
+                hp: 0,
+                damage: 0,
+                mana: 101,
+                armor: 0,
+                duration: 5,
+                cost: 229,
+            },
+        ]
+    }
+}
+
+#[derive(Debug, Default, Clone)]
+struct Character {
+    hp: u32,
+    damage: u32,
+    armor: u32,
+    mana: u32,
+    status_effects: Vec<Spell>,
+}
+
+impl Character {
+    fn hit_damage(&self, other: &Self) -> u32 {
+        let damage = self.damage.saturating_sub(other.armor);
+        if damage > 0 {
+            damage
+        } else {
+            1
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn part1_1() {
+        let boss = Character {
+            hp: 13,
+            damage: 8,
+            ..Default::default()
+        };
+        let player = Character {
+            hp: 10,
+            mana: 250,
+            ..Default::default()
+        };
+        let mut used_mana = Vec::new();
+        for spell in Spell::get_all() {
+            used_mana.push(round(player.clone(), boss.clone(), spell, 0));
+        }
+        let mut result = u32::MAX;
+        for state in used_mana {
+            if state.get_value() < result {
+                result = state.get_value();
+            }
+        }
+        assert_eq!(result, 226);
+    }
+
+    #[test]
+    fn part1_2() {
+        let boss = Character {
+            hp: 14,
+            damage: 8,
+            ..Default::default()
+        };
+        let player = Character {
+            hp: 10,
+            mana: 250,
+            ..Default::default()
+        };
+        let mut used_mana = Vec::new();
+        for spell in Spell::get_all() {
+            used_mana.push(round(player.clone(), boss.clone(), spell, 0));
+        }
+        let mut result = u32::MAX;
+        for state in used_mana {
+            if state.get_value() < result {
+                result = state.get_value();
+            }
+        }
+        assert_eq!(result, 641);
+    }
+
+    #[test]
+    fn part2() {
+        let result = process_part2("");
+        assert_eq!(result, 0);
+    }
+}
diff --git a/y2015/src/days/mod.rs b/y2015/src/days/mod.rs
index fac8109..60520cf 100644
--- a/y2015/src/days/mod.rs
+++ b/y2015/src/days/mod.rs
@@ -22,3 +22,5 @@ pub mod d19;
 pub mod d20;
 
 pub mod d21;
+
+pub mod d22;