The winner of the game is the first person to check the opponent three times. As you can imagine, white holds a significant advantage in this variant.
The same as regular chess, except the game finishes when one player checks the other three times. The checks do not have to be consecutive. Checkmate also wins the game.
Looking for checks is an extremely important part of the game. If you don't look for checks, you will never find checkmate. Encourage your student to look for checks with every one of their pieces, every turn. Also point out that blocking checks is usually good, but not so great in this game, because it allows the piece of capture the blocker, therefore getting another check.