diff --git a/tests/testDamage.cpp b/tests/testDamage.cpp
new file mode 100644
index 0000000..b325ac3
--- /dev/null
+++ b/tests/testDamage.cpp
@@ -0,0 +1,159 @@
+#include "testHarness.h"
+#include "vf/Damage.h"
+
+using namespace vf;
+
+namespace {
+
+ArmorSet fullSet(Armor::Material material) {
+    ArmorSet set;
+    set.equip(makeArmor(material, Armor::Slot::Helmet));
+    set.equip(makeArmor(material, Armor::Slot::Chestplate));
+    set.equip(makeArmor(material, Armor::Slot::Leggings));
+    set.equip(makeArmor(material, Armor::Slot::Boots));
+    return set;
+}
+
+void enchantWholeSet(ArmorSet& set, EnchantKind kind, int level) {
+    for (Armor& piece : set.pieces) addEnchant(piece.enchants, kind, level);
+}
+
+DamageEvent hitFor(DamageType type, float amount) {
+    DamageEvent event;
+    event.source = environmentSource(type);
+    event.amount = amount;
+    return event;
+}
+
+void idleTicks(CombatStats& stats, EffectSet& effects, int count) {
+    for (int i = 0; i < count; ++i) tickCombat(stats, effects);
+}
+
+} // namespace
+
+VF_TEST(diamondArmorReducesMeleeDamageByTheVanillaCurve) {
+    ArmorSet diamond = fullSet(Armor::Material::Diamond);
+    CHECK_EQ(diamond.totalPoints(), 20);
+    CHECK_NEAR(diamond.totalToughness(), 8.0f, 0.001f);
+    CHECK_NEAR(armorReduction(20, 8.0f, 10.0f), 3.0f, 0.001f);
+
+    ArmorSet leather = fullSet(Armor::Material::Leather);
+    CHECK_EQ(leather.totalPoints(), 7);
+    CHECK_NEAR(leather.totalToughness(), 0.0f, 0.001f);
+    // Weak armour hits the points/5 floor against a big blow.
+    CHECK_NEAR(armorReduction(7, 0.0f, 20.0f), 20.0f * (1.0f - 1.4f / 25.0f), 0.001f);
+}
+
+VF_TEST(voidAndStarveDamageIgnoreArmorEntirely) {
+    EffectSet none;
+    uint32_t rng = 7u;
+    CombatStats player;
+    player.armor = fullSet(Armor::Material::Diamond);
+
+    CombatResult voided = applyDamage(player, none, hitFor(DamageType::Void, 6.0f), rng);
+    CHECK(voided.applied);
+    CHECK_NEAR(voided.healthLost, 6.0f, 0.001f);
+    CHECK_EQ(voided.armorDurabilityLost, 0);
+
+    player.health = 20.0f;
+    CombatResult melee = applyDamage(player, none, hitFor(DamageType::Melee, 6.0f), rng);
+    CHECK(melee.applied);
+    CHECK(melee.healthLost < 3.0f);
+    CHECK(melee.armorDurabilityLost > 0);
+}
+
+VF_TEST(invulnerabilityWindowSwallowsWeakerFollowUpsButNotStrongerOnes) {
+    EffectSet none;
+    uint32_t rng = 11u;
+    CombatStats player;
+
+    CombatResult first = applyDamage(player, none, hitFor(DamageType::Melee, 5.0f), rng);
+    CHECK(first.applied);
+    CHECK_NEAR(player.health, 15.0f, 0.001f);
+    CHECK_EQ(player.invulnerableTicks, invulnerabilityTicks);
+
+    CombatResult weaker = applyDamage(player, none, hitFor(DamageType::Melee, 3.0f), rng);
+    CHECK(weaker.blockedByInvulnerability);
+    CHECK(!weaker.applied);
+    CHECK_NEAR(player.health, 15.0f, 0.001f);
+
+    CombatResult stronger = applyDamage(player, none, hitFor(DamageType::Melee, 8.0f), rng);
+    CHECK(stronger.applied);
+    CHECK_NEAR(player.health, 12.0f, 0.001f);
+
+    idleTicks(player, none, invulnerabilityTicks);
+    CHECK_EQ(player.invulnerableTicks, 0);
+    CombatResult fresh = applyDamage(player, none, hitFor(DamageType::Melee, 2.0f), rng);
+    CHECK(fresh.applied);
+    CHECK_NEAR(player.health, 10.0f, 0.001f);
+}
+
+VF_TEST(starvationLandsEveryTickBecauseItIgnoresTheInvulnerabilityWindow) {
+    EffectSet none;
+    uint32_t rng = 3u;
+    CombatStats player;
+
+    for (int i = 0; i < 5; ++i) {
+        CombatResult starve = applyDamage(player, none, hitFor(DamageType::Starve, 1.0f), rng);
+        CHECK(starve.applied);
+    }
+    CHECK_NEAR(player.health, 15.0f, 0.001f);
+}
+
+VF_TEST(attackChargeRampsBackToFullAndScalesSwingDamage) {
+    EffectSet none;
+    CombatStats attacker;
+    attacker.baseAttackDamage = 7.0f;
+    attacker.attackSpeed = 4.0f;
+    CHECK_EQ(attackCooldownTicks(4.0f), 5);
+
+    registerSwing(attacker);
+    CHECK_NEAR(attackCharge(attacker), 0.0f, 0.001f);
+    EnchantSet bare;
+    float coldSwing = meleeAttackDamage(attacker, bare, none, false, false, false);
+    CHECK_NEAR(coldSwing, 7.0f * 0.2f, 0.001f);
+
+    for (int i = 0; i < 5; ++i) tickCombat(attacker, none);
+    CHECK_NEAR(attackCharge(attacker), 1.0f, 0.001f);
+    float fullSwing = meleeAttackDamage(attacker, bare, none, false, false, false);
+    CHECK_NEAR(fullSwing, 7.0f, 0.001f);
+
+    // The bar caps, extra ticks change nothing.
+    for (int i = 0; i < 20; ++i) tickCombat(attacker, none);
+    CHECK_NEAR(attackCharge(attacker), 1.0f, 0.001f);
+}
+
+VF_TEST(sharpnessAndCriticalHitsStackOnTopOfBaseSwingDamage) {
+    EffectSet none;
+    CombatStats attacker;
+    attacker.baseAttackDamage = 7.0f;
+    attacker.attackChargeTicks = 5;
+
+    EnchantSet plain;
+    EnchantSet sharp;
+    CHECK(addEnchant(sharp, EnchantKind::Sharpness, 5));
+
+    CHECK_NEAR(meleeAttackDamage(attacker, plain, none, false, false, false), 7.0f, 0.001f);
+    CHECK_NEAR(meleeAttackDamage(attacker, sharp, none, false, false, false), 10.0f, 0.001f);
+    CHECK_NEAR(meleeAttackDamage(attacker, sharp, none, false, false, true), 15.0f, 0.001f);
+
+    EnchantSet smite;
+    CHECK(addEnchant(smite, EnchantKind::Smite, 4));
+    CHECK_NEAR(meleeAttackDamage(attacker, smite, none, false, false, false), 7.0f, 0.001f);
+    CHECK_NEAR(meleeAttackDamage(attacker, smite, none, true, false, false), 17.0f, 0.001f);
+}
+
+VF_TEST(strengthAddsAndWeaknessRemovesFlatMeleeDamage) {
+    CombatStats attacker;
+    attacker.baseAttackDamage = 7.0f;
+    attacker.attackChargeTicks = 5;
+    EnchantSet bare;
+
+    EffectSet strong;
+    applyEffect(strong, makeEffect(EffectKind::Strength, 2, 200));
+    CHECK_NEAR(meleeAttackDamage(attacker, bare, strong, false, false, false), 13.0f, 0.001f);
+
+    EffectSet weak;
+    applyEffect(weak, makeEffect(EffectKind::Weakness, 1, 200));
+    CHECK_NEAR(meleeAttackDamage(attacker, bare, weak, false, false, false), 3.0f, 0.001f);
+