Orbital Drop Shock Troopers, or ODSTs for short, are the toughest of the tough among the human ground forces (Spartans excepted). They are basically heavily armed and highly trained paratroopers.

The Elite Minor, or blue Elite, is the weaker and more common version. This one is armed with a Carbine, the rough equivalent of the Battle Rifle, and probably more dangerous than Halo 1's standard weapon for the Elite Minor, which was a plasma rifle. In Halo 1, Elites also sometimes used needlers and plasma grenades. Elites have full body rechargeable shields that deflect energy and projectile weapons. Like the Jackal's armband shield, however, it can be completely drained by an alt-fire charge from the plasma pistol, leaving him open to damage from other weapons. When an Elite's shields are drained, he will generally seek cover. When his health becomes low, he will charge you in a suicide manuever. When near you, they will usually attempt a melee attack. Sangheili refers to all Elites, not just Minor ones.

The Master Chief, John-117, is a Spartan II cyborg with Mjolnir armor. In Halo 1, he wore Mark V armor, but is expected to get an upgrade to Mark VI in the sequel. He is shown here brandishing a shotgun. Like Covenant Elites, he has a full-body self-recharging energy shield that deflects energy and projectile weapons. It was, at least in part, reverse engineered from Covenant technology. Due to the Mjolnir armor and their numerous genetic and cybernetic enhancements, the Master Chief and the other Spartans are tougher, faster, and stronger than all other human ground forces.

In Halo 1, Jackals only carried plasma pistols, but as you can see from this shot, in Halo 2 they wield other weapons, including plasma rifles and possibly even needlers. The armband shields they carry are not as effective as the full body shields used by Elites, but they will deflect most projectile weapons and are even good against plasma rifles. The best strategies against Jackals are to try and shoot areas unprotected by the shield, which are easier to hit when they are in motion, or to use the alt-fire of a plasma pistol to drain the shield and then switch to another weapon while it cools. Like the Elite's shields, a drained Jackal shield will recharge over time. Jackals with drained shields, like Elites, will also often retreat and take cover while their shields recharge. Grenades can be effective against Jackals, especially when used behind them where their shields do not protect. The Halo 2 manual refers to Jackals as "excellent shots" and indicates they have higher status than Grunts.

Sgt. Johnson survived Halo 1 after being killed (at least once, if not more) and was not assimilated by the Flood because of Boren's Syndrome, a disease he contracted from hanging around too many plasma grenades. Johnson declined treatment for his Boren's Syndrome to get back into battle more quickly. The effects of the disease on his nervous system led the Flood infection form to reject his body. Boren's Syndrome is named after Brannon Boren, keeper of the Halo Bible and, as of this writing, working on Matrix Online. Johnson is shown here with a battle rifle. In Halo 2, you can exchange weapons with the Sarge or other human units.

Grunts are Covenant "cannon fodder" according to the books, and make up the bulk of their ground forces. Despite their all-too-often retreats in Halo 1, the novels describe them as almost heroic in their persistence. In Halo 1, Grunts wielded plasma pistols or needlers, and often carried plasma grenades. SpecOps grunts, wearing black uniforms, also carried Fuel Rod Guns similar to those that Hunters have molded into their arms and the alternate firing mode for the Banshee. (The Halo PC manual reports them using plasma rifles but not needlers, but I believe this is an error, as I have definitely seen them use needlers but never recall seeing one use a plasma rifle.) Normally grunts are orange or red. Red ones seem to be tougher, and may be Grunts Major, similar to the major/minor divisions seen among Elites and in several kinds of enemies in the Marathon series. Grunts are usually only dangerous in groups, and tend to congregate near stronger units such as Jackals and Elites. The Halo 2 manual indicates that when an Elite is nearby, Grunts are less likely to flee, but will panic when faced by "superior forces".