Duel Blackjack by ProxyLiveSolutions: headline RTP 99.44%.
An RTP of 99.44% means a house edge of 0.56% — the expected cost is 0.56 units per 100 staked over the long run, whatever a single session does.
Against our catalogue the number is above the median of 96.13%, higher than 100% of the games whose RTP we verified. That comparison matters more than the raw figure, because "96%" only sounds generous next to nothing.
Duel Blackjack has a published RTP of 99.44%, a house edge of 0.56%. We have not yet found a casino serving it at a different RTP build.
Duel Blackjack is a ProxyLiveSolutions game, so the outcome is produced by the studio's certified RNG rather than by the casino, and it is not provably fair in the cryptographic sense — you cannot recompute a spin from a seed. What the casino does control is which RTP build it serves. That is the real variable, and it is measurable.