Normal
From Halopedia, the Halo wiki
Summary
Normal is the default difficulty rating; it's not too hard, but not too easy. The enemies will not cower as much, and few Grunts will throw Plasma Grenades. It is ranked 2nd in the list of 4 difficulties. In addition this difficulty is another good starting level for beginners to the Halo series as is Easy Mode. Normal mode has the most realistic strength, Master Chief, Elites and all, although intelligence, enemy accuracy, and enemy numbers are most realistic in Legendary. The strength of Master Chief and the Elites are evenly balanced out in Normal, so that's why this is the most realistic mode.
Normal is a little harder than easy but players can move through levels relatively easily. This difficulty doesn’t ruin your gaming experience by being too hard and is hard enough to impede progress.
The most dangerous thing from 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 of, and will more often than not run if the elite with them is killed, which is also fairly easy. Drones and Jackals (with the exeption to snipers) are 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 the player's weakness as to which is the hardest.
On the level Regret, where you have to kill the Prophet of Regret, his advanced fuel rod gun will drain around one third of your energy shield. He is fairly easy to kill when you jump on him and start punchimg him. Only if you stay on him for a considerably long time will he teleport away. The honor guards protecting him will not do much damage unless they have energy swords.
When you encounter the flood, most plasma weapons are average and most human weapons are a bit better. The most efective weapon is the energy sword, which will kill a Combat Form in one hit. The second most effective is the Sentinel Beam, followed by the shotgun. The flood's unarmed attacks are not that worrying on their own, but if large groups attack you or you get hit from behind, then you have an extremely good chance of being killed.
