Rerolling in Backpack Brawl involves a complex system of item rarity upgrades and downgrades, influenced by lucky, golden and cursed clovers:

• Each lucky clover adds a 30% chance, and each golden clover adds a 40% chance to upgrade an item's rarity.
• Each cursed clover adds a 30% chance to downgrade an item's rarity.
• Items are created one at a time, with upgrade attempts occurring before downgrade attempts.
• An item can only be upgraded or downgraded once, never both.
• There's a total of 500% upgrade/downgrade chance available.
• Mythic items cannot be upgraded further, and common items cannot be downgraded.
• A "bag pity counter" ensures you get a bag item at least every 11th item.
• The pity bag's rarity matches the item it replaced, using the highest available rarity if necessary.

This system allows for strategic use of clovers to influence your item pool, while maintaining balance and preventing excessive manipulation of item rarities.