Gear

Two kinds.

Tradable. Found in dungeons, sellable, and you can leave it at home before a run.

Soulbound. Bound to that Warrior. Cannot be traded, moved, or left behind. Dies with it.

Soulbound gear is what makes deep floors survivable, so a Warrior that has survived a lot is genuinely stronger than a fresh one. You cannot buy that.

It also means every death burns something, which keeps loot from piling up forever as more runs happen.