Tried using Evade against other player

[Fdruid]

He was about to fight the king, so as a last attempt to stop him from taking the win, I thought that if he had Evade, he would be forced to defend instead of attacking, and thus wouldn't die but wouldn't kill the king (to give the rest of the players a chance to take him out before the win).

I think the effect wore off, but I'm not sure if it works against the King. Would this have worked as intended?

[Almanac]

Evade would only work if someone attacked him, and it would push him out. If he attacked the king (or any other player/creature for that matter,) it wouldn't take effect.

If you mean that someone attacked him and it still didn't work, perhaps he had lionheart breastplate equipped. The card does also wear off after the end of the user's next turn, too.

[ChaosConvexum]

I take it you used Wyld's Warning on the opponent. Evasion is only triggered when the one with the effect is attacked, not the other way around (otherwise, with Ranger's Cloak equipped and in a Forest tile, one could never conduct an attack hoping to kill someone). If you wanted to prevent that other player from attacking the King using Evasion, you would've had to have them attacked by you of somebody else before their turn. That way, with Evasion active, they would've been forced to flee from that tile (hopefully on a non-palace tile, or, even better, getting routed if they had no other way to flee on an empty tile), regardless of how much damage they sustained during the Evasion.