My friend was actually considering doing something exactly like this. But this will never be as popular as regular dice games...
2x: My wager: 0.0000982 BTC;I can win: 0.0001 BTC + wager back
3x: My wager: 0.00009865 BTC;I can win: 0.00005 BTC + wager back
6x: My wager: 0.00009892 BTC;I can win: 0.00002 BTC + wager back
Why would anyone create a game with more than 2x profit, when there's more to lose than to win? Or I'm not understanding this correctly...
The thing that looks to have the best potential is the player-player competition, But could you allow a single game from funds of multiple players? (for example ten users with 0.1 in a one game to have 1 as a bankroll) to allow little users to seriously invest in the bankroll (and not go broke from few roles before the rules of numbers are in effect.
This would be abused by sockpuppet accounts. 9 sockpuppets vs 1 player, the chances are 9 against 1. There's no way to make anything except 1v1 fair, unless the games are invite only/passworded, and you're playing with 9 people you know.
for x3 payout, player can select <3 or >4, player win odds is 1/3
so creator win odds is 2/3
for x6 payout, player can select <2 or >5, player win odds is 1/6
so creator win odds is 5/6
therefore creator always have an edge,
that is why casino house will give you x10 or even x100 payout, meaning they can only win 1/10 or 1/100 of money wagered.