Thanks for writing in, Chief.
The Zero Trophies Revenge can happen in two instances:
- Someone attacks you via Revenge.
- You attack someone else via Revenge.
Getting zero trophies from one of these attacks occurrs via the matchmaking system.
For example: you are attacked by GoblinKing99. You wait two days before getting Revenge. Over the course of those two days, GoblinKing99 has gone from having as many trophies as you, to having way fewer. Because GoblinKing99 has less trophies during the Revenge than he did during the first battle, the score you receive after beating him will also be lower, as you are now considered to be the more powerful village. This score can result in a zero if the game determines that GoblinKing99 is no longer an even match.