Is it valid to get out of a trade based on wording?

[Shinigami]

Here is something that happened a while back that seriously left me a bit salty for a bit.

A player was going up against a monster and someone played a mate card. I had a card that would make the monster go away immediately ending the round. Or so I thought at the time. I thought that if I made the main monster go away, the mate would follow. It was decided that the mate would stay.

Now, the problem is that I had cut a deal with the person fighting the monster and mate. I told him that if he gave me the item his hireling had equipped I would use my card to end the combat by making the monster go away. He said, "sure, ill give it to you after the fight is done".

See where im going with this? I made the main monster go away, but the mate stayed. Other people played other cards so he still wasn't able to beat the mate by itself. So he used the hireling to run away thus destroying the item he promised me for playing my card. Is this legal?

[Andrew Hackard]

First, you were wrong: Mate copies a monster, but it is itself a distinct monster that must also be defeated. Making one go away doesn't affect the other (which is why we advise discarding the Mate card for simplicity).

That said, your opponent's play was legal. He's allowed to use any resources at hand during the fight or Run Away phase, even if those resources were promised to someone else. Yes, it sucks that he did that, but it was a legal play and probably a smart one, too.

[Shinigami]

Fair enough. Thanks for the quick reply.