diff --git a/src/data/items.h b/src/data/items.h
index 15d769cea8..a0ccc67ff8 100644
--- a/src/data/items.h
+++ b/src/data/items.h
@@ -2863,7 +2863,7 @@ const struct Item gItems[] =
         .itemId = ITEM_SILVER_POWDER,
         .price = 100,
         .holdEffect = HOLD_EFFECT_BUG_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sSilverPowderDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3009,7 +3009,7 @@ const struct Item gItems[] =
         .itemId = ITEM_METAL_COAT,
         .price = 100,
         .holdEffect = HOLD_EFFECT_STEEL_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sMetalCoatDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3199,7 +3199,7 @@ const struct Item gItems[] =
         .itemId = ITEM_SOFT_SAND,
         .price = 100,
         .holdEffect = HOLD_EFFECT_GROUND_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sSoftSandDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3213,7 +3213,7 @@ const struct Item gItems[] =
         .itemId = ITEM_HARD_STONE,
         .price = 100,
         .holdEffect = HOLD_EFFECT_ROCK_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sHardStoneDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3227,7 +3227,7 @@ const struct Item gItems[] =
         .itemId = ITEM_MIRACLE_SEED,
         .price = 100,
         .holdEffect = HOLD_EFFECT_GRASS_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sMiracleSeedDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3241,7 +3241,7 @@ const struct Item gItems[] =
         .itemId = ITEM_BLACK_GLASSES,
         .price = 100,
         .holdEffect = HOLD_EFFECT_DARK_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sBlackGlassesDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3255,7 +3255,7 @@ const struct Item gItems[] =
         .itemId = ITEM_BLACK_BELT,
         .price = 100,
         .holdEffect = HOLD_EFFECT_FIGHTING_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sBlackBeltDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3269,7 +3269,7 @@ const struct Item gItems[] =
         .itemId = ITEM_MAGNET,
         .price = 100,
         .holdEffect = HOLD_EFFECT_ELECTRIC_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sMagnetDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3283,7 +3283,7 @@ const struct Item gItems[] =
         .itemId = ITEM_MYSTIC_WATER,
         .price = 100,
         .holdEffect = HOLD_EFFECT_WATER_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sMysticWaterDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3297,7 +3297,7 @@ const struct Item gItems[] =
         .itemId = ITEM_SHARP_BEAK,
         .price = 100,
         .holdEffect = HOLD_EFFECT_FLYING_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sSharpBeakDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3311,7 +3311,7 @@ const struct Item gItems[] =
         .itemId = ITEM_POISON_BARB,
         .price = 100,
         .holdEffect = HOLD_EFFECT_POISON_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sPoisonBarbDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3325,7 +3325,7 @@ const struct Item gItems[] =
         .itemId = ITEM_NEVER_MELT_ICE,
         .price = 100,
         .holdEffect = HOLD_EFFECT_ICE_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sNeverMeltIceDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3339,7 +3339,7 @@ const struct Item gItems[] =
         .itemId = ITEM_SPELL_TAG,
         .price = 100,
         .holdEffect = HOLD_EFFECT_GHOST_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sSpellTagDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3353,7 +3353,7 @@ const struct Item gItems[] =
         .itemId = ITEM_TWISTED_SPOON,
         .price = 100,
         .holdEffect = HOLD_EFFECT_PSYCHIC_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sTwistedSpoonDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3367,7 +3367,7 @@ const struct Item gItems[] =
         .itemId = ITEM_CHARCOAL,
         .price = 9800,
         .holdEffect = HOLD_EFFECT_FIRE_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sCharcoalDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3381,7 +3381,7 @@ const struct Item gItems[] =
         .itemId = ITEM_DRAGON_FANG,
         .price = 100,
         .holdEffect = HOLD_EFFECT_DRAGON_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sDragonFangDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,
@@ -3395,7 +3395,7 @@ const struct Item gItems[] =
         .itemId = ITEM_SILK_SCARF,
         .price = 100,
         .holdEffect = HOLD_EFFECT_NORMAL_POWER,
-        .holdEffectParam = 10,
+        .holdEffectParam = 20,
         .description = sSilkScarfDesc,
         .pocket = POCKET_ITEMS,
         .type = 4,