What if instead of discarding a card, he took his -1 card token each time he played an action? That seems slightly less powerful.
Oh, that's good. I mean it may or may not work in practice, but it's better than my idea.
I actually like that, because if he plays cards that draw, it's essentially making all of them draw 1 less, but doesn't punish a non-drawing hand.
Right, except that it draws you one less card at the end of your turn.
After thinking about it, I'm guessing it's still way too harsh. It's a very cool idea, though.
Also, since this is a "draw up to x" card, it counters its own attack, which could be cool. It's probably pretty harsh anyway, it's like -1 card on every action that has at least +1 card on it. But it doesn't hurt any non-drawing action. But yeah, all your labs are now cantrips? Sounds too powerful.
How about: Until your next turn, whenever a player would draw a card, he must first discard a card.
Aside from Fragsnap's beautifully illustrated point, that just still sounds too strong. Maybe if the discarding were after he drew, instead of before. And then you'd just have to deal with draw-up-to-x's. But discarding once for each card draw sounds way too strong, notice that it's stronger than the -1 card token for cards that draw more than one card. In fact no action can ever increase your handsize while that is in play; no action can ever keep your handsize the same! (Exceptions include things that incrase handsize without drawing; like Envoy).
Hey, "resolve" is a thing now, so let's use that:
Until your next turn, directly after another player resolves an action, he discards a card.This is the most similar to your original card; the only difference is that he discards the card after the action instead of before, which makes it less painful for cards that draw.
Ok, but that's still too painful for cards that don't draw. So instead:
While this is in play, directly after another player resolves an action, he discards down to 5 cards.Ok, so this will have no effect on cantrips or cards that don't draw. But it is a bigger blow to cards that do draw, now your opponent can never increase handsize. But he can continue to draw through his deck, finding the best 5 cards. Changed to "while this is in play" because Throning does nothing anyway.
I like that version, because I like the concept of basically giving your opponent a hand-size limit.