Gameitall 
Considering that most of the violence in the Halo series has been against aliens and never been overly violent in terms of FPS, I’ve always found it weird that all the Halo games at this point has been rated M by the ESRB, meaning that the game cannot be sold to anyone under the age of 18.
So it’s interesting enough to know that Halo 5 Guardians is rated T for Teen by the ESRB, being the first FPS from the Halo series to reach the more family friendly rating. The latest ESRB rating gives the T rating due to Blood, Mild Language, Violence. Specifically, the rating gives us what we expect from the title, listing “Players use pistols, machine guns, grenade launchers, and futuristic weapons to kill alien and human enemies… Battles are highlighted by realistic gunfire, explosions, and occasional blood-splatter effects. Characters can also use “assassinations” to kill characters by snapping their necks, or by stabbing them with bladed weapons.”
The Mild Language portion of the rating range from the basic use of ass, to some interesting insults, two of which mentioned in the list includes ” “I have copulated…with your genetic progenitors!”; and “Your father was a filthy colo and your mother was a hole in the wall!”
Halo Wars and Halo Spartan Assault were the only other Halo titles to hit the T rating, it was stated that this was because of their isometric view, being a strategy game and a twin-stick shooter.
Teen rating seems fine to me. It’s a little less intense than say, the CoD series; which by all means little kids have no reason to be playing until their teens at least.