Spartan Officer is a Halo 3 multiplayer achievement. It is earned when the player gains 50 experience points in a certain playlist and a rank of at least Lieutenant on Xbox Live. This achievement gives 25 gamerscore to the player.
It is represented by a gold plate with an eagle holding three black arrows and a black thunderbolt, with three pips behind it.
It unlocks the Rogue Helmet for multiplayer use.
- It has been said by many players that they got the achievement at the same time as the Vidmaster Challenge: Lightswitch Achievement, and it didn't go through. Others did not get the achievement after advancing to a Highest Skill of 10, skipping the last Gunnery Sergeant rank and going straight to Lieutenant, Grade 1.
- If you have achieved the Spartan Officer Badge and haven't gotten the achievement, you can still obtain the achievement by getting a lieutenant rank in any of the new playlist-specific ranking systems.