Yes. It is. Every Bitcoin casino allows you to use any form of betting pattern. Operators are well aware of the limitations of such strategies. Even if the casino loses for a moment, they know they’ll make a profit in the end. Every game runs with an RTP <100%, so the casino has an edge in the long run. E.g., players playing Dice with Martingale will reach the betting or bankroll limits resulting in the player’s loss.