• Be sure to take your time and let your shield recharge, the easiest way to get yourself killed is by rushing in when your shield is depleted.
• Whenever there is a break in the action you should be sure all your weapons are reloaded because you don't know when your next chance to reload may be.
• When switching weapons you should be sure to choose the two that will suit your needs the best, having the shotgun and the assault rifle won't do you much good at long range.
• Grenades are meant to be thrown, you can carry eight at a time and they are plentiful in every level, use them often.
• Whenever possible use the melee from behind on any enemy or shoot them in their sleep (Grunts).
• The motion tracker is a good tool, use it often but remember it only sees the enemy if they are moving.
• Friendly fire is on so you and your teammates need to be careful when firing, melee attacking, and throwing grenades in close combat.
• Watch all navpoints because they have been placed on your heads up display for a reason.
• Never hold down the trigger of the pistol, it affects your accuracy.
• Remember that Covenant plasma weapons cannot be reloaded, so always be aware of fresher weapons.
• Every foe has a weak spot; however it is not always the head.
• Vehicles can be taken places that you might think are not possible so be sure to try.

• Whenever the Covenant, Sentinels, and Flood are fighting it is sometimes better to wait for them to finish and pick off the stragglers then it is to try to jump in and fight them all.
• Vehicles are not always the best choice, but when choosing a vehicle make sure it suits your mission needs.
• Listen to your enemies, they will give away their position or tell you if they have thrown a grenade.
• The Marines are on your side and will help you finish the mission, protect them and they will protect you.
• Be aggressive with Elites, Jackals, and Grunts; being passive is an easy way to get yourself killed.
• Be careful of flood carrier forms as they can ignite grenades that are around them when they “pop.”
• If you are driving the Warthog pick up some marines if possible.
• Hunters always travel in groups of two.
• When the Covenant have vehicles or gun emplacements you need to be sure to take them out first as they can kill you quickly.
• If you encounter a large amount of Covenant, take down the Jackals and Grunts first. The last thing you want is a grenade from a Grunt or an overcharged plasma pistol bolt hitting you while you are engaging an Elite or Hunter.
• Remember when you are invisible that you can throw grenades and melee and cannot be seen.
• When you first pick up an over-shield you are invincible until it fills up your shields.
• Remember that plasma weapons slow the enemies' movements when they are hit, use this to your advantage.
• Watch for the armor color of the covenant, it may give away what weapon they are using or how skilled they are.
• Never try to go toe-to-toe with an Elite toting a energy blade.
• The plasma pistol, when charged, can overload a Jackals shield or drop a Sentinel dead.
• Listen to Cortana, she usually can help you complete your mission.