Early in the page, one internal link for UX: browse the full Items Database to compare similar on-hit items.
Every time you land an attack, there is an independent 2% roll to “BONK” that hit for 20× damage. The effect does not require any setup and is available from the start of the game.
If you make 100 attacks, you’ll see ~2 BONKs on average. The more hits you generate per minute, the more BONK opportunities you create. Consider exploring weapons with dense hit patterns (e.g., Aura, Firestaff, Bananarang) to increase total rolls.
Luck affects loot/upgrade rarity, not on-hit proc chances. Don’t rely on Luck to improve Big Bonk’s 2% rate—focus on increasing hit frequency instead.