diff --git a/Cargo.lock b/Cargo.lock
index 6d7dd1e..3c9c21a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -591,6 +591,7 @@ dependencies = [
  "bevy_rapier2d",
  "leafwing-input-manager",
  "petgraph",
+ "seldom_state",
 ]
 
 [[package]]
@@ -4816,6 +4817,23 @@ dependencies = [
  "tiny-skia",
 ]
 
+[[package]]
+name = "seldom_state"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5db0767975eeb39d99493b23adc55b14d7106c333c06dd85774fa2cb909b79d5"
+dependencies = [
+ "bevy_app",
+ "bevy_derive",
+ "bevy_ecs",
+ "bevy_log",
+ "bevy_math",
+ "bevy_utils",
+ "either",
+ "leafwing-input-manager",
+ "variadics_please",
+]
+
 [[package]]
 name = "self_cell"
 version = "1.2.2"
diff --git a/Cargo.toml b/Cargo.toml
index 5ac7fc0..148865f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,6 +10,7 @@ bevy = { version = "0.18.0", features = ["bevy_remote"] }
 bevy_rapier2d = "0.33.0"
 leafwing-input-manager = "0.20.0"
 petgraph = { version = "0.8.3" }
+seldom_state = { version = "0.16.0", features = ["leafwing_input"] }
 
 [profile.dev]
 opt-level = 1
diff --git a/src/combat/attack.rs b/src/combat/attack.rs
index eceaf54..0c89016 100644
--- a/src/combat/attack.rs
+++ b/src/combat/attack.rs
@@ -5,6 +5,8 @@ use std::time::Duration;
 use bevy::prelude::*;
 use bevy_rapier2d::prelude::*;
 
+use crate::{GROUP_ATTACK, GROUP_INTERACTIVE, GROUP_STATIC};
+
 /// Contains logic for attack-related calculations
 #[derive(Component, Clone, Debug, Reflect)]
 #[reflect(Component, Clone, Debug)]
@@ -33,6 +35,7 @@ impl AttackArea {
             max_distance,
         }
     }
+
     /// Returns attack area bundle with everything needed
     pub fn bundle(
         damage: f32,
@@ -41,6 +44,7 @@ impl AttackArea {
         position: Vec2,
         half_area: Vec2,
         facing_left: bool,
+        affinity: Group,
     ) -> impl Bundle {
         let origin_x = if facing_left { position.x - half_area.x } else { position.x + half_area.x };
         (
@@ -49,6 +53,10 @@ impl AttackArea {
             
             // Collision
             Transform::from_xyz(position.x, position.y, 0.),
+            CollisionGroups::new(
+                GROUP_ATTACK,
+                GROUP_STATIC | GROUP_INTERACTIVE | affinity,
+            ),
             Collider::cuboid(half_area.x, half_area.y),
 
             // AttackAreaOrigin
@@ -73,3 +81,12 @@ impl AttackArea {
         self.damage * EaseFunction::QuinticOut.sample_unchecked(total_multiplier)
     }
 }
+
+/// System that updates AttackArea timers and despawns those who timed out
+pub fn update_attack_areas(mut commands: Commands, time: Res<Time>, areas: Query<(Entity, &mut AttackArea)>) {
+    for (area_id, mut area) in areas {
+        if area.tick(time.delta()) {
+            commands.entity(area_id).despawn();
+        }
+    }
+}
diff --git a/src/combat/mod.rs b/src/combat/mod.rs
index a8e6a95..e425307 100644
--- a/src/combat/mod.rs
+++ b/src/combat/mod.rs
@@ -1,3 +1,25 @@
 //! This module contains core concepts of the combat system
 
+use bevy::prelude::*;
+
 pub mod attack;
+
+/// Combat health component
+#[derive(Component, Clone, Copy, PartialEq, Debug, Default, Reflect)]
+#[reflect(Component, Clone, PartialEq, Debug, Default)]
+pub struct Health {
+    /// Current health value
+    pub current: f32,
+    /// Maximum health value
+    pub max: f32,
+}
+
+impl Health {
+    /// Constructs new health component
+    pub fn new(max: f32) -> Self {
+        Self {
+            current: max,
+            max,
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index bc03532..82c458a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,14 +10,27 @@ pub mod graph;
 pub mod input;
 pub mod player;
 pub mod plugin;
+pub mod states;
 pub mod timer;
 
 use bevy::prelude::*;
+use bevy_rapier2d::prelude::*;
 
 use crate::{player::Player, timer::BpmTimer};
 
 const PIXELS_PER_METER: f32 = 16.;
 
+/// Collision group for static entities (walls, floors, etc)
+pub const GROUP_STATIC: Group = Group::GROUP_1;
+/// Collision group for interactive entities (doors, buttons, etc)
+pub const GROUP_INTERACTIVE: Group = Group::GROUP_2;
+/// Collision group for player and player-related entities
+pub const GROUP_FRIENDLY: Group = Group::GROUP_3;
+/// Collision group for enemy-related entities
+pub const GROUP_ENEMY: Group = Group::GROUP_4;
+/// Collision group for attack-related entities
+pub const GROUP_ATTACK: Group = Group::GROUP_5;
+
 /// Returns pixel measurement for given length in meters
 #[inline(always)] pub const fn meters(length: f32) -> f32 { PIXELS_PER_METER * length }
 
diff --git a/src/player/mod.rs b/src/player/mod.rs
index d1afba7..9c486f0 100644
--- a/src/player/mod.rs
+++ b/src/player/mod.rs
@@ -5,11 +5,10 @@ use bevy_rapier2d::prelude::*;
 use leafwing_input_manager::prelude::*;
 
 use crate::{
-    meters,
-    input::{
+    GROUP_ATTACK, GROUP_ENEMY, GROUP_FRIENDLY, GROUP_INTERACTIVE, GROUP_STATIC, input::{
         DefaultInputMap,
         PlayerInput,
-    }
+    }, meters
 };
 
 pub mod systems;
@@ -51,11 +50,19 @@ impl Player {
             RigidBody::KinematicPositionBased,
             KinematicCharacterController::default(),
             ActiveCollisionTypes::default() | ActiveCollisionTypes::KINEMATIC_STATIC,
+            CollisionGroups::new(
+                GROUP_FRIENDLY,
+                GROUP_STATIC | GROUP_INTERACTIVE | GROUP_ENEMY | GROUP_ATTACK,
+            ),
             Collider::cuboid(meters(0.3), meters(0.9)),
             ActiveEvents::COLLISION_EVENTS,
             Sleeping::disabled(),
 
+            // State
+            crate::states::Free,
+
             Children::spawn((
+                // Camera
                 Spawn((
                     Name::new("Player camera"),
                     Camera2d,
diff --git a/src/plugin.rs b/src/plugin.rs
index a7efe34..a38b630 100644
--- a/src/plugin.rs
+++ b/src/plugin.rs
@@ -3,6 +3,7 @@
 use bevy::prelude::*;
 use bevy_rapier2d::prelude::*;
 use leafwing_input_manager::prelude::*;
+use seldom_state::prelude::*;
 
 use crate::*;
 
@@ -18,6 +19,8 @@ impl Plugin for GamePlugin {
 
             InputManagerPlugin::<input::PlayerInput>::default(),
             InputManagerPlugin::<input::DebugInput>::default(),
+            
+            StateMachinePlugin::default(),
         ))
         .add_systems(Startup, setup)
         .add_systems(Update, (
diff --git a/src/states.rs b/src/states.rs
new file mode 100644
index 0000000..2e75afd
--- /dev/null
+++ b/src/states.rs
@@ -0,0 +1,24 @@
+//! Commonly used entity states
+
+use bevy::prelude::*;
+
+/// Entity is not doing anything special
+#[derive(Component, Clone, Copy, PartialEq, Eq, Debug, Default, Reflect)]
+#[reflect(Component, Clone, PartialEq, Debug, Default)]
+pub struct Free;
+
+/// Entity is acting and cannot do something else
+#[derive(Component, Clone, Copy, PartialEq, Eq, Debug, Default, Reflect)]
+#[reflect(Component, Clone, PartialEq, Debug, Default)]
+pub struct Acting {
+    /// How much time left before action ends
+    pub beats_remaining: u32,
+}
+
+/// Entity is awaiting a specific set of actions
+#[derive(Component, Clone, Copy, PartialEq, Eq, Debug, Default, Reflect)]
+#[reflect(Component, Clone, PartialEq, Debug, Default)]
+pub struct ActionWindow {
+    /// How much time left before window ends
+    pub beats_remaining: u32,
+}