It's an Order is one of the achievements and trophies available in Dead Island: Riptide. The achievement/trophy is pretty self-explanatory, all you need to do is mark an enemy then have your co-op partner finish them off. It will unlock upon the death of the 100th enemy.
Notes[]
- This can be done on any enemy, not just zombies.
- The final blow has to be struck by your partner, but you can damage them to low health.
- This can be done with any number of partners, not just one. You only have to make sure that you aren't the one to kill the enemy.