- “Hordes of aliens vie to destroy you, but nerves of steel and a quick trigger finger give you a solid chance to prevail.”
- “Face firm resistance from competent, determined enemies, but burn through enough ammo and you will eventually triumph.”
- “Hordes of enemy forces converge to destroy you. Show no mercy. Recommended for players with first person shooter experience.”— Description in Halo 5: Guardians.
- “The enemy will not relent, but a considered strategy should earn you a victory. Recommended for players with RTS experience.”— Description in Halo Wars 2
Normal is not too hard, but not too easy. The enemies will not cower as much, and a few Grunts will throw Plasma Grenades. While Normal mode reasonably represents the firepower and strength for both the UNSC and the Covenant, intelligence, enemy accuracy, and enemy numbers are the most realistic in Heroic.
The icon for the Normal difficulty setting is represented with a shield that has the Marathon Logo encrusted into the center. Over the shield is a UNSC combat knife from right to left. The Halo 3: ODST design notably lacks the combat knife and is replaced with the Supressed SMG. In Halo 4, the design lacked the marathon symbol and the combat knife is replaced by a machete. The new icon introduced in Halo: The Master Chief Collection incorporates a hunter shield with a single Energy Sword, and as with the Halo 4 icon, has no marathon symbol.
The most dangerous enemy at close range is an Elite with an Energy Sword, and from a distance is a Sniper Jackal with a Beam Rifle. Grunts are still very easy to dispatch and will more often than not run if the Elite or Brute leading them is killed, which is also fairly easy. Drones and Jackals (with the exception to snipers) are generally the second easiest to kill, even with their unique capabilities. Elites, Brutes, and Hunters are around the same overall in difficulty to kill. It mainly depends on a player's weaknesses as to which enemy is harder to kill.
When the player encounters the Flood, most plasma weapons are average and most human weapons are a bit better. The most effective weapon is the Energy Sword, which can take down a Combat Form in one slash. The second most effective is the Shotgun. The Flood's unarmed attacks are not that worrying on their own, but if large groups attack the player or he/she gets hit from behind, then the player has an extremely high chance of being killed.
Marines are pretty much average; they can easily gun down smaller enemies such as Grunts and in most case handle their own against Jackals, but will fall quickly against Elites. They can also be killed relatively easily by explosive ballistics which they won't always dodge. Due to these facts, it isn't uncommon to see allies firing blindly or not engaging their foe's properly, even when it's head on. It's often better to let them handle on weaker enemies themselves while you focus on the tougher ones.
- In Halo 3, Normal difficulty or higher is required for you to collect skulls.
- Halo: Reach requires you to play on Normal or higher to unlock achievements.
- In Halo 3, you unlock Spartan EVA armor for beating Campaign on Normal difficulty.
- Halo 3, Halo 3: ODST, Halo: Reach, Halo: Combat Evolved Anniversary and Halo 4 keep track of whether you finished Normal Campaign on Solo or Co-op.
- In Halo 3: ODST, the combat knife on the difficulty shield icon is replaced with an M7S Caseless Submachine Gun.