The comment for people who don't want to give that cesspool ad revenue.

You can bleed out while playing solo. You can order your squad to revive you, but they only have a few seconds to get to you, and if you’re in the middle of a firefight they may die trying. We’ve deliberately tuned Heroic and Legendary around the number of checkpoint loads we expect, not the number of times a player gets downed and then revived. Certain damage sources bypass the downed state.

Your squad is tuned to take care of themselves if you want to play like any Halo game, not stealing your kills or getting in your way. If ordered to attack they will do everything they can to kill your target. Some care is required, they’re not a win button and can get downed or die if you order them into a dangerous situation, particularly on higher difficulties. They’re effective with almost every weapon in the game, can drive or gun in every vehicle, and have access to most player abilities, including grenades, melee and thrusters.

Overall, we’ve upped enemy damage output, responsiveness and speed to address there always being a squad of friendly AI, and the new player abilities. For example, Hunters are faster and more dangerous, are very hard to tackle from the front and have a couple of new tricks up their sleeves to handle multiple, agile targets. Along with the traditional Halo difficulty levers (higher accuracy, higher damage, reduced delays between bursts, etc.) we’ve given certain enemies faster melee attacks on higher difficulties, making player reaction time more important and keeping a single enemy melee from being an opportunity for a player to whale on the enemy from behind.

We’ve touched the tuning on every enemy and every weapon in the game, testing across all difficulties and solo, 2-player and 4-player co-op, and have addressed as much of the feedback on Halo 4 AI as possible.