This is the historical implementation of five card draw poker. You are paired off against 3 other opponents. Every day you get an allowance of money you can bet with. As long as you have money, and you haven't completely fleeced all your opponents, you can play. Each day you play increases your daily allowance.
You will be dealt five cards initially, and must bet based on those. If you don't like your hand, you can fold to give up. If you call, you must contribute chips to the pot at the current betting level. If you raise, you increase the betting level by one. Once everyone calls, you move on to the next phase.
During the discard phase, you may discard up to three of your cards. You will receive new cards to replace them.
As before, the betting starts again. If everyone else folds, you win by default. If the game is called, then all remaining players show their cards and the highest hand wins.