diff --git a/src/battle_util.c b/src/battle_util.c
index c15c46a09..ea8ee4cde 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -9660,7 +9660,7 @@ static inline uq4_12_t GetAttackerItemsModifier(u32 battlerAtk, uq4_12_t typeEff
     {
     case HOLD_EFFECT_METRONOME:
         percentBoost = min((gBattleStruct->sameMoveTurns[battlerAtk] * GetBattlerHoldEffectParam(battlerAtk)), 100);
-        return sPercentToModifier[percentBoost];
+        return uq4_12_add(sPercentToModifier[percentBoost], UQ_4_12(1.0));
         break;
     case HOLD_EFFECT_EXPERT_BELT:
         if (typeEffectivenessModifier >= UQ_4_12(2.0))
diff --git a/test/battle/hold_effect/metronome.c b/test/battle/hold_effect/metronome.c
new file mode 100644
index 000000000..76cd27c6f
--- /dev/null
+++ b/test/battle/hold_effect/metronome.c
@@ -0,0 +1,156 @@
+#include "global.h"
+#include "test/battle.h"
+
+ASSUMPTIONS
+{
+    gItems[ITEM_METRONOME].holdEffect == HOLD_EFFECT_METRONOME;
+}
+
+const uq4_12_t MetronomeMultipliers[] = {
+    UQ_4_12(1.0),
+    UQ_4_12(1.2),
+    UQ_4_12(1.4),
+    UQ_4_12(1.6),
+    UQ_4_12(1.8),
+    UQ_4_12(2.0),
+    UQ_4_12(2.0)
+};
+
+#define METRONOME_TURNS (ARRAY_COUNT(MetronomeMultipliers))
+
+SINGLE_BATTLE_TEST("Metronome Item gradually boosts power of consecutively used moves by 20%, up to 100%")
+{
+    s16 damage[METRONOME_TURNS];
+    u32 j;
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET) { Item(ITEM_METRONOME); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        for (j = 0; j < METRONOME_TURNS; ++j) {
+            TURN { MOVE(player, MOVE_TACKLE); }
+        }
+    } SCENE {
+        for (j = 0; j < METRONOME_TURNS; ++j) {
+            ANIMATION(ANIM_TYPE_MOVE, MOVE_TACKLE, player);
+            HP_BAR(opponent, captureDamage: &damage[j]);
+        }
+    } THEN {
+        for (j = 0; j < METRONOME_TURNS; ++j) {
+            EXPECT_MUL_EQ(damage[0], MetronomeMultipliers[j], damage[j]);
+        }
+    }
+}
+
+SINGLE_BATTLE_TEST("Metronome Item's boost is reset if the attacker uses a different move")
+{
+    s16 damage[2];
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET) { Item(ITEM_METRONOME); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { MOVE(player, MOVE_TACKLE); }
+        TURN { MOVE(player, MOVE_QUICK_ATTACK); }
+        TURN { MOVE(player, MOVE_TACKLE); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TACKLE, player);
+        HP_BAR(opponent, captureDamage: &damage[0]);
+
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_QUICK_ATTACK, player);
+
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TACKLE, player);
+        HP_BAR(opponent, captureDamage: &damage[1]);
+    } THEN {
+        EXPECT_EQ(damage[0], damage[1]);
+    }
+}
+
+SINGLE_BATTLE_TEST("Metronome Item's boost is reset if the move fails")
+{
+    s16 damage[2];
+    KNOWN_FAILING; //https://github.com/rh-hideout/pokeemerald-expansion/issues/3251
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET) { Item(ITEM_METRONOME); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { MOVE(player, MOVE_TACKLE); }
+        TURN { MOVE(opponent, MOVE_PROTECT); MOVE(player, MOVE_TACKLE); }
+        TURN { MOVE(player, MOVE_TACKLE); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TACKLE, player);
+        HP_BAR(opponent, captureDamage: &damage[0]);
+
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TACKLE, player);
+        HP_BAR(opponent, captureDamage: &damage[1]);
+    } THEN {
+        EXPECT_EQ(damage[0], damage[1]);
+    }
+}
+
+SINGLE_BATTLE_TEST("Metronome Item counts called moves instead of the calling move")
+{
+    s16 damage[2];
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET) { Item(ITEM_METRONOME); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { MOVE(player, MOVE_METRONOME, WITH_RNG(RNG_METRONOME, MOVE_TACKLE)); }
+        TURN { MOVE(player, MOVE_METRONOME, WITH_RNG(RNG_METRONOME, MOVE_TACKLE)); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TACKLE, player);
+        HP_BAR(opponent, captureDamage: &damage[0]);
+
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TACKLE, player);
+        HP_BAR(opponent, captureDamage: &damage[1]);
+    } THEN {
+        EXPECT_MUL_EQ(damage[0], UQ_4_12(1.2), damage[1]);
+    }
+}
+
+SINGLE_BATTLE_TEST("Metronome Item counts charging turn of moves for its attacking turn", s16 damage)
+{
+    u32 item;
+
+    KNOWN_FAILING; // https://github.com/rh-hideout/pokeemerald-expansion/issues/3250
+    PARAMETRIZE {item = ITEM_NONE; }
+    PARAMETRIZE {item = ITEM_METRONOME; }
+    GIVEN {
+        ASSUME(gBattleMoves[MOVE_SOLAR_BEAM].effect == EFFECT_SOLAR_BEAM);
+        PLAYER(SPECIES_WOBBUFFET) { Item(item); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { MOVE(player, MOVE_SOLAR_BEAM); }
+        TURN { SKIP_TURN(player); }
+    } SCENE {
+        MESSAGE("Wobbuffet used Solar Beam!");
+        MESSAGE("Wobbuffet took in sunlight!");
+        MESSAGE("Foe Wobbuffet used Celebrate!");
+        MESSAGE("Congratulations, 1!");
+        MESSAGE("Wobbuffet used Solar Beam!");
+        HP_BAR(opponent, captureDamage: &results[i].damage);
+    } FINALLY {
+        EXPECT_MUL_EQ(results[0].damage, UQ_4_12(1.2), results[1].damage);
+    }
+}
+
+SINGLE_BATTLE_TEST("Metronome Item doesn't increase damage per hit of multi-hit moves")
+{
+    s16 damage[3];
+    GIVEN {
+        ASSUME(gBattleMoves[MOVE_FURY_ATTACK].effect == EFFECT_MULTI_HIT);
+        PLAYER(SPECIES_WOBBUFFET) { Item(ITEM_METRONOME); }
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { MOVE(player, MOVE_FURY_ATTACK); }
+        TURN { MOVE(player, MOVE_FURY_ATTACK); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_FURY_ATTACK, player);
+        HP_BAR(opponent, captureDamage: &damage[0]);
+        HP_BAR(opponent, captureDamage: &damage[1]);
+        MESSAGE("Hit 5 time(s)!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_FURY_ATTACK, player);
+        HP_BAR(opponent, captureDamage: &damage[2]);
+    } THEN {
+        EXPECT_MUL_EQ(damage[0], UQ_4_12(1.2), damage[2]); // Got bonus once for the second turn
+        EXPECT_EQ(damage[0], damage[1]); // Do not get the bonus while still inside the first turn
+    }
+}