diff --git a/sharedUI/src/commonTest/kotlin/org/shahondin1624/DamageMonitorTest.kt b/sharedUI/src/commonTest/kotlin/org/shahondin1624/DamageMonitorTest.kt
new file mode 100644
index 0000000..15ffd05
--- /dev/null
+++ b/sharedUI/src/commonTest/kotlin/org/shahondin1624/DamageMonitorTest.kt
@@ -0,0 +1,245 @@
+package org.shahondin1624
+
+import org.shahondin1624.model.attributes.Attribute
+import org.shahondin1624.model.attributes.AttributeType
+import org.shahondin1624.model.attributes.Attributes
+import org.shahondin1624.model.charactermodel.DamageMonitor
+import org.shahondin1624.model.charactermodel.DamageTrackType
+import org.shahondin1624.model.charactermodel.createDamageMonitor
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+/**
+ * Tests for DamageMonitor damage tracking, wound modifiers,
+ * toggle behavior, and overflow transitions.
+ */
+class DamageMonitorTest {
+
+    // Body=6, Willpower=4 -> physicalMax = 7 + (6/2) = 10, stunMax = 7 + (4/2) = 9, overflowMax = (6/2) = 3
+    private val testAttributes = Attributes(
+        body = Attribute(AttributeType.Body, 6),
+        agility = Attribute(AttributeType.Agility, 3),
+        reaction = Attribute(AttributeType.Reaction, 3),
+        strength = Attribute(AttributeType.Strength, 3),
+        willpower = Attribute(AttributeType.Willpower, 4),
+        logic = Attribute(AttributeType.Logic, 3),
+        intuition = Attribute(AttributeType.Intuition, 3),
+        charisma = Attribute(AttributeType.Charisma, 3),
+        edge = 3
+    )
+
+    private fun freshMonitor(): DamageMonitor = DamageMonitor(testAttributes)
+
+    // ---- Max calculations ----
+
+    @Test
+    fun stunMaxIsBasePlusHalfWillpower() {
+        val monitor = freshMonitor()
+        // 7 + (4 / 2.0).toInt() = 7 + 2 = 9
+        assertEquals(9, monitor.stunMax())
+    }
+
+    @Test
+    fun physicalMaxIsBasePlusHalfBody() {
+        val monitor = freshMonitor()
+        // 7 + (6 / 2.0).toInt() = 7 + 3 = 10
+        assertEquals(10, monitor.physicalMax())
+    }
+
+    @Test
+    fun overflowMaxIsHalfBody() {
+        val monitor = freshMonitor()
+        // (6 / 2.0).toInt() = 3
+        assertEquals(3, monitor.overflowMax())
+    }
+
+    // ---- Initial state ----
+
+    @Test
+    fun freshMonitorHasZeroDamage() {
+        val monitor = freshMonitor()
+        assertEquals(0, monitor.stunCurrent())
+        assertEquals(0, monitor.physicalCurrent())
+        assertEquals(0, monitor.overflowCurrent())
+    }
+
+    // ---- Setting damage values ----
+
+    @Test
+    fun withStunDamageSetsCorrectValue() {
+        val monitor = freshMonitor().withStunDamage(5)
+        assertEquals(5, monitor.stunCurrent())
+    }
+
+    @Test
+    fun withPhysicalDamageSetsCorrectValue() {
+        val monitor = freshMonitor().withPhysicalDamage(7)
+        assertEquals(7, monitor.physicalCurrent())
+    }
+
+    @Test
+    fun withOverflowDamageSetsCorrectValue() {
+        val monitor = freshMonitor().withOverflowDamage(2)
+        assertEquals(2, monitor.overflowCurrent())
+    }
+
+    @Test
+    fun damageIsClamtedToMax() {
+        val monitor = freshMonitor()
+        val overStun = monitor.withStunDamage(100)
+        assertEquals(9, overStun.stunCurrent()) // clamped to stunMax=9
+
+        val overPhys = monitor.withPhysicalDamage(100)
+        assertEquals(10, overPhys.physicalCurrent()) // clamped to physicalMax=10
+
+        val overFlow = monitor.withOverflowDamage(100)
+        assertEquals(3, overFlow.overflowCurrent()) // clamped to overflowMax=3
+    }
+
+    @Test
+    fun damageIsClampedToZero() {
+        val monitor = freshMonitor()
+        val negStun = monitor.withStunDamage(-5)
+        assertEquals(0, negStun.stunCurrent())
+    }
+
+    // ---- Wound modifier ----
+
+    @Test
+    fun woundModifierIsZeroWithNoDamage() {
+        assertEquals(0, freshMonitor().woundModifier())
+    }
+
+    @Test
+    fun woundModifierIsZeroUnderThreshold() {
+        // 1 and 2 physical damage -> no wound modifier yet
+        assertEquals(0, freshMonitor().withPhysicalDamage(1).woundModifier())
+        assertEquals(0, freshMonitor().withPhysicalDamage(2).woundModifier())
+    }
+
+    @Test
+    fun woundModifierNegOneAtThreePhysical() {
+        val monitor = freshMonitor().withPhysicalDamage(3)
+        assertEquals(-1, monitor.woundModifier())
+    }
+
+    @Test
+    fun woundModifierNegTwoAtSixPhysical() {
+        val monitor = freshMonitor().withPhysicalDamage(6)
+        assertEquals(-2, monitor.woundModifier())
+    }
+
+    @Test
+    fun woundModifierScalesWithDamage() {
+        val monitor = freshMonitor().withPhysicalDamage(9)
+        assertEquals(-3, monitor.woundModifier())
+    }
+
+    // ---- Toggle damage box ----
+
+    @Test
+    fun toggleEmptyBoxMarksDamage() {
+        val monitor = freshMonitor()
+        // Toggle position 3 when current=0 -> should set to 3
+        val toggled = monitor.toggleDamageBox(DamageTrackType.Physical, 3)
+        assertEquals(3, toggled.physicalCurrent())
+    }
+
+    @Test
+    fun toggleFilledBoxHealsToPreviousPosition() {
+        val monitor = freshMonitor().withPhysicalDamage(5)
+        // Toggle position 3 when current=5 -> position 3 is filled, heal to 2
+        val toggled = monitor.toggleDamageBox(DamageTrackType.Physical, 3)
+        assertEquals(2, toggled.physicalCurrent())
+    }
+
+    @Test
+    fun toggleLastFilledBoxClearsDamage() {
+        val monitor = freshMonitor().withPhysicalDamage(3)
+        // Toggle position 1 -> heal to 0
+        val toggled = monitor.toggleDamageBox(DamageTrackType.Physical, 1)
+        assertEquals(0, toggled.physicalCurrent())
+    }
+
+    @Test
+    fun toggleStunTrackWorks() {
+        val monitor = freshMonitor()
+        val damaged = monitor.toggleDamageBox(DamageTrackType.Stun, 5)
+        assertEquals(5, damaged.stunCurrent())
+
+        // Toggle lower position to heal
+        val healed = damaged.toggleDamageBox(DamageTrackType.Stun, 3)
+        assertEquals(2, healed.stunCurrent())
+    }
+
+    @Test
+    fun toggleOverflowTrackWorks() {
+        val monitor = freshMonitor()
+        val damaged = monitor.toggleDamageBox(DamageTrackType.Overflow, 2)
+        assertEquals(2, damaged.overflowCurrent())
+
+        val healed = damaged.toggleDamageBox(DamageTrackType.Overflow, 1)
+        assertEquals(0, healed.overflowCurrent())
+    }
+
+    // ---- Physical-to-overflow transition ----
+
+    @Test
+    fun physicalCanBeFilled() {
+        val monitor = freshMonitor().withPhysicalDamage(10) // physicalMax=10
+        assertEquals(10, monitor.physicalCurrent())
+        assertEquals(0, monitor.overflowCurrent())
+    }
+
+    @Test
+    fun overflowCanBeSetWhenPhysicalIsFull() {
+        val monitor = freshMonitor()
+            .withPhysicalDamage(10) // fill physical track
+            .withOverflowDamage(2)  // then add overflow
+        assertEquals(10, monitor.physicalCurrent())
+        assertEquals(2, monitor.overflowCurrent())
+    }
+
+    @Test
+    fun fullPhysicalAndFullOverflow() {
+        val monitor = freshMonitor()
+            .withPhysicalDamage(10)
+            .withOverflowDamage(3) // overflowMax=3
+        assertEquals(10, monitor.physicalCurrent())
+        assertEquals(3, monitor.overflowCurrent())
+    }
+
+    // ---- createDamageMonitor ----
+
+    @Test
+    fun createDamageMonitorStartsAtMaxValues() {
+        val monitor = createDamageMonitor(testAttributes)
+        assertEquals(monitor.stunMax(), monitor.stunCurrent())
+        assertEquals(monitor.physicalMax(), monitor.physicalCurrent())
+        assertEquals(monitor.overflowMax(), monitor.overflowCurrent())
+    }
+
+    // ---- Wound modifier updates past thresholds ----
+
+    @Test
+    fun woundModifierUpdatesCorrectlyAsDamageIncreases() {
+        var monitor = freshMonitor()
+        assertEquals(0, monitor.woundModifier())
+
+        monitor = monitor.withPhysicalDamage(1)
+        assertEquals(0, monitor.woundModifier())
+
+        monitor = monitor.withPhysicalDamage(3)
+        assertEquals(-1, monitor.woundModifier())
+
+        monitor = monitor.withPhysicalDamage(6)
+        assertEquals(-2, monitor.woundModifier())
+
+        monitor = monitor.withPhysicalDamage(9)
+        assertEquals(-3, monitor.woundModifier())
+
+        // Heal back
+        monitor = monitor.withPhysicalDamage(2)
+        assertEquals(0, monitor.woundModifier())
+    }
+}