Talk:Treasure Jailer, Sonderdach/@comment-7153241-20160824012813/@comment-11372432-20160824021839

It's apparently mandatory. It's in case you can't mill for whatever reason. Right now, the only thing stopping that is deckout and that makes the damage moot lol.

Basically, you have to mill 3, but if you can't, for some odd reason, you don't take any damage. If it was phrased "mill 3, take 1 damage", then you'd still take the damage even if you couldn't mill. Of course, optional mill would have been best and would have made this card actually playable.