The Half Blood Prince
Based on: Seven card stud
This game is the same as seven card stud, with a few exceptions:
The King with the ax is wild.
If you get a red jack face-up, you get to take three chips out of the pot.
If you get a black jack face-up, you have to put three extra chips into the pot.
Hufflepuff Poker
Based on: Seven card stud
This is the "everyone gets a wild card" game. Each player's first face up card is wild- for that player only.
The Prisoner of Azkaban
Based on: Seven card stud
The cards are arranged on the table like in the picture below. Each player first picks any two cards from the table, and doesn't show them to anyone. Then they take one card and flip it face-up, and put it in front of them. The basic idea is the same as seven card stud, only you are randomly picking your seven cards out of those already on the table. Black aces are wild.