PlayingCards/PokerStud

Not certain, but:

Some cards are dealt to you face up.
A part of the first round of betting is then based upon those cards of your opponents you can see.

In some studs, you end up with more cards in total - and make the best hand you can from those face up and the ones only you have seen. In others there is a central set of face up cards which can be used by anyone as a part of their hand.

Obviously, the added information both of your hands quality (that other people now know) and about theirs makes the betting more interesting. Still an exercise of pure probability until you see their bets and know their habits, but more complex (and thus intersting) than basic.

The most well-known example is probably Texas Hold 'Em. You are dealt two cards. Round of betting. Three cards are laid out face up. Round of betting. One card is laid out face up. Round of betting. Final card is laid out face up. Final round of betting. Your hand is the best five cards from the five (shared) face-up ones and your personal face-down ones.
The betting in this is rather constrained. To ensure that things make a start, there is something called a blind (because you pay it without looking at your cards). The player to the left of dealer must bet the small blind, and the player to their left must bet the large blind, which is twice the small blind. In the first two rounds of betting, each raise must be equal to the large blind. In the last two, each raise must be equal to twice the large blind. No more than three raises are permitted per round.

: You know, this should probably be named stud-poker, since poker-stud sounds horribly like a PornStar? NickName?. --Vitenka