Remorseless Punishment

Sorcery

Target opponent loses 5 life unless that player discards two cards or sacrifices a creature or planeswalker. Repeat this process once.

2016-01-22:
The player can’t choose to discard two cards unless they have at least two cards in hand. Similarly, that player can’t choose to sacrifice a creature or planeswalker unless they control one. This means that if the target opponent doesn’t have two cards in hand and doesn’t control a creature or planeswalker, that player will lose 5 life and then lose 5 life again.
2016-01-22:
No player may take any actions between the two times the player goes through the process.
2016-01-22:
Any abilities that trigger while Remorseless Punishment is resolving will be put on the stack after it has completely resolved.
2016-04-08:
The same player chooses both times. In a multiplayer game, you can’t choose a different opponent to repeat the process.