The Far Cry Poker Cheat\n\n In other words simply save your game before you start playing the highest-stakes game and then go into shove mode, pushing all-in on every hand. If you lose, just reload your saved game. If you win, exit the poker game, save, and then try again.
This achievement is extremely easy, you just need to progress until you reach the second island. Once there in Thurston Town, there is a sidequest called Father's Burden. Accept the quest and follow the markers, you'll speak to an old gambler who wants you to win his money back from the mercenaries at the bar.
