The first player to act picks which game gets played, hand by hand.
Button and blinds.
Three cards to everyone first — then the first player to act chooses which of five HORSE-family games the hand becomes, and dealing continues accordingly.
Follows whichever game got picked.
Follows whichever game got picked.
Worth knowing: A meta-game more than a single ruleset — good "how do we even run this" hosting-guide content.