Texas Hold'em uses a standard 52-card deck. Each player gets 2 private hole cards and uses any combination of hole cards plus 5 community cards to make the best 5-card hand.
Hand ranking: Straight Flush, Four of a Kind, Full House, Flush, Straight, Three of a Kind, Two Pair, One Pair, High Card.
Flow: blinds post, preflop betting, flop (3 cards), turn (1 card), river (1 card), showdown. If one player remains before showdown, that player wins the pot.
Actions: fold, check, call, raise, all-in. You have 45 seconds to act; timeout auto-checks when legal or auto-folds otherwise.