18 tiers.
Only one direction: up.

With my promo code, here's what you get on Duel.com: if a game runs at 96% RTP, the house edge is 4% — 2% goes straight into your rakeback, instantly, no conditions. Every Monday, I add back up to +0.95% more depending on your VIP rank. So a 96% RTP game can effectively play up to ~99% RTP in your hands.

* 2% is illustrative, based on a standard 96% RTP slot (4% house edge). The real house edge — and so your real return — varies by game and by RTP setting, since providers ship multiple RTP configurations per title.

* Minigames (Mines, Keno, etc.) run 0% house edge on Duel.com — there's no edge to share, so they don't count toward qualifying wager.