diff --git a/build.gradle b/build.gradle
index f3722a2..632fd46 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlinVersion = '1.3.50'
+    ext.kotlinVersion = '1.3.60'
 
     repositories {
         mavenLocal()
@@ -25,7 +25,7 @@ allprojects {
         gdxVersion = '1.9.10'
         roboVMVersion = '2.3.7'
         box2DLightsVersion = '1.4'
-        ashleyVersion = '1.7.0'
+        ashleyVersion = '1.7.3'
         aiVersion = '1.8.0'
         ktxVersion = '1.9.10-b2'
     }
diff --git a/core/src/me/msoucy/ptures/model/Creature.kt b/core/src/me/msoucy/ptures/model/Creature.kt
new file mode 100644
index 0000000..b0057cd
--- /dev/null
+++ b/core/src/me/msoucy/ptures/model/Creature.kt
@@ -0,0 +1,41 @@
+package me.msoucy.ptures.model
+
+import com.badlogic.gdx.math.MathUtils.clamp
+
+class Stats(var atk : Int, var def : Int, var spd : Int, var hp : Int)
+
+class Creature {
+    var genes = Stats(5,5,5,5)
+    var growth = Stats(5,5,5,5)
+    var level = 1
+    var currentHp = 1
+    val statuses = mutableListOf<Status>()
+
+    val atk : Int get() = statFormula(genes.atk, growth.atk)
+    val def : Int get() = statFormula(genes.atk, growth.atk)
+    val spd : Int get() = statFormula(genes.atk, growth.atk)
+    val maxHp : Int get() = statFormula(genes.atk, growth.atk)
+
+    fun apply(dmg : Damage) {
+        currentHp = clamp(currentHp - dmg.power, 0, maxHp)
+    }
+
+    fun addStatus(status : Status) {
+        if(status !in statuses)
+        {
+            statuses.add(status)
+            status.onAdd(this)
+        }
+    }
+
+    fun removeStatus(status : Status) {
+        statuses.remove(status)
+    }
+
+    fun fullHeal() {
+        currentHp = maxHp
+        statuses.clear()
+    }
+
+    private fun statFormula(gene : Int, growth : Int) = (2 * gene + growth) * level / 100 + 5
+}
\ No newline at end of file
diff --git a/core/src/me/msoucy/ptures/model/Engine.kt b/core/src/me/msoucy/ptures/model/Engine.kt
new file mode 100644
index 0000000..75afd03
--- /dev/null
+++ b/core/src/me/msoucy/ptures/model/Engine.kt
@@ -0,0 +1,13 @@
+package me.msoucy.ptures.model
+
+class Engine(vararg val creatures : Creature) {
+    init {
+        assert(creatures.isNotEmpty())
+    }
+
+    var currentCreature = 0
+
+    val attacker : Creature get() {
+        return creatures[currentCreature]
+    }
+}
\ No newline at end of file
diff --git a/core/src/me/msoucy/ptures/model/Skills.kt b/core/src/me/msoucy/ptures/model/Skills.kt
new file mode 100644
index 0000000..ee2c4b1
--- /dev/null
+++ b/core/src/me/msoucy/ptures/model/Skills.kt
@@ -0,0 +1,72 @@
+package me.msoucy.ptures.model
+
+@DslMarker
+annotation class SkillMarker
+
+enum class Target {
+    Selected,
+    Self,
+    Others,
+    Opponents,
+    All
+}
+
+enum class Attribute {
+    Neutral,
+    Stone,
+    Fire,
+    Water,
+    Air,
+    Wood
+}
+
+class Damage(val power : Int) {
+    var target = Target.Selected
+    var accuracy = 100
+}
+
+@SkillMarker
+class Skill(val name : String, val attribute : Attribute) {
+    val preSteps = mutableListOf<Pair<Status, Target>>()
+    val damageSteps = mutableListOf<Damage>()
+    val postSteps = mutableListOf<Pair<Status, Target>>()
+
+    fun damage(power : Int, block : Damage.() -> Unit = {}) {
+        val d = Damage(power)
+        d.block()
+        damageSteps.add(d)
+    }
+
+    fun addStatus(status : Status, target : Target = Target.Selected) {
+        postSteps.add(Pair(status, target))
+    }
+}
+
+fun skill(name : String, attribute : Attribute = Attribute.Neutral, block : Skill.() -> Unit) : Skill {
+    val ret = Skill(name, attribute)
+    ret.block()
+    return ret
+}
+
+val Tackle = skill("Tackle") {
+    damage(20)
+}
+
+val DoubleKick = skill("Double Kick") {
+    repeat(2) {
+        damage(35) {
+            accuracy = 85
+        }
+    }
+}
+
+val DoubleEdge = skill("Double Edge") {
+    damage(20)
+    damage(10) {
+        target = Target.Self
+    }
+}
+
+val Fly = skill("Fly") {
+    addStatus(Flying(), Target.Self)
+}
\ No newline at end of file
diff --git a/core/src/me/msoucy/ptures/model/Status.kt b/core/src/me/msoucy/ptures/model/Status.kt
new file mode 100644
index 0000000..3baaccb
--- /dev/null
+++ b/core/src/me/msoucy/ptures/model/Status.kt
@@ -0,0 +1,42 @@
+package me.msoucy.ptures.model
+
+sealed class Status {
+
+    open fun onAdd(creature : Creature) {
+        // Do nothing
+    }
+
+    open fun onTurnEnd(engine : Engine) {
+        // Do nothing by default
+    }
+}
+
+sealed class VisibleStatus(val label : String = "") : Status()
+
+sealed class CountdownStatus(var turns : Int) : Status()
+{
+    override fun onTurnEnd(engine : Engine) {
+        turns--
+        if(turns == 0) {
+            onCountdownReached(engine)
+            engine.attacker.removeStatus(this)
+        }
+    }
+
+    open fun onCountdownReached(engine : Engine) {
+    }
+}
+
+object KnockedOut : VisibleStatus("ko")
+object Burned : VisibleStatus("burned") {
+    override fun onTurnEnd(engine : Engine) {
+        // Deal a small amount of damage
+    }
+}
+object Stunned : VisibleStatus("stunned")
+object Poisoned : VisibleStatus("poisoned")
+class Flying : CountdownStatus(1) {
+    override fun onCountdownReached(engine: Engine) {
+        super.onCountdownReached(engine)
+    }
+}