The cards. You and your opponent each get one card, 2 through Ace. Higher card wins the showdown. That's the whole game underneath.

The bet. Check (stay in for free) or bet (raise the stakes). They can call, fold, or raise back. Standard nerve stuff.

The tell. Every opponent takes a different amount of time to decide — and how long they take says something. Some hesitate only when they're weak. Some fake it.

The catch. They're timing you too. Decide too slow, too often, and they start reading you right back.