Edit: this is an out of date submission. I have updated it hereRoyal Advisor | Action - Duration - Command | $4
Now and at the start of your next turn: You may play a non-Duration non-Command Action card from your hand twice. Each other player may play a copy of it from the Supply, leaving it there.
Figured I'd go for some bonus points -- a new way of interacting. This throne room lets other players play that card for free, on their turn. This is a throne room + next turn throne room for $4, what gives? Well, it can't throne itself, that's for starters. And it's restricted further, throning a Moat this turn nets you with a hand size two greater than when you started, minus the action. But it
also increase all of your opponents hand size by two, without costing them an action. So you might only be willing to throne cards your opponents don't benefit from (terminal $?)
It's "may" play an action, so you can always choose not to play a card. If you don't play the card, no one gets to.
And lastly, you can play cards where the pile has run out or non-supply cards, then your opponents don't get the bonus.
I've made this play non-Duration cards following the conventions of fellow Duration-Command cards Captain and Prince. Frankly, it's too much track multiple players having played a Duration card without it ever being in-play.
Open to feedback. I'm considering giving this a "+1 Card" on play, since this throne room hates playing +Cards, so it could make sense to at least give it 1 card. I still think it could cost $4 then, and this card is more fun if used more often.