Most cashback offers cap each payment and set a minimum loss below which nothing is paid. Some also restrict the games that count, leaving out table games or particular slots, so losses there never qualify. A cap turns a percentage into a fixed ceiling: a tenth of a large loss can be cut to a small flat amount. Reading the cap and the qualifying games together shows the most the offer can ever pay back.
Cashback is credited automatically at some casinos and only on request at others, sometimes within a short claim window. The payment usually arrives on a fixed day after the period closes. An offer built on losses deserves one more thought: it rewards the weeks that went badly, and it should never be a reason to keep playing toward a larger refund. Treated as a small cushion, it does no real harm.
Cashback is almost always calculated on net losses: deposits minus withdrawals and the remaining balance over the period, or stakes minus wins. A player who ends the week ahead receives nothing, whatever was staked along the way. Some offers count only losses made with real money, leaving out anything lost from bonus funds. The formula in the terms, often a single sentence, decides how much of a bad week really qualifies.