Anyone attempting to kill another one of your creatures with a spell or damage needs to deal with Pippin first, and that ward cost makes it just a little bit more difficult
This adaptation was initially developed by Klaus Teuber for two players in a tournament-style format, but since then seven expansions have been released, all which add numerous cards to spice up play
If each opponent chose snitch, Prisoner's Dilemma deals 8 damage to each of them
However, the shenanigans that newhat pointed out can adapt to this restriction
You dont get to have hundreds of buildings of steel and glass or transportation infrastructure weaving through boroughs without the strength and speed of the Riveteers workforce coming into play
This is especially true if you can block and trade off the creature you stole, and really true if attacking means they can block off all their 1/1s, leaving a Lovestruck Beast unable to attack