Boons are permanent upgrades you choose after clearing each floor. Every choice sticks for the rest of the run and stacks with the others.
After a floor boss falls, you're offered three boon cards. Pick one to apply it to your party and descend. Effects are cumulative across the whole expedition — grab +damage twice and it multiplies.
Each card shows its rarity (border color), a symbol for the kind of effect, and who it helps — the whole party or a specific role (a Tank/Healer boon is only offered when that role is in your party). The same symbols appear on the in-run boon tracker under the minimap.
In idle/spectator mode the game auto-picks for you after a short countdown.
Each card first rolls a rarity by these odds, then a random boon of that tier. The odds are adjustable in the admin panel (they always total 100%). Current odds: