M90 shotgun/Gameplay

Campaign

 * One of the most dominating weapons in the Halo Trilogy, the Shotgun shows its most effective side in The Library in Halo: Combat Evolved and in Sacred Icon in Halo 2, where equipping one allows the user to plow through hordes of Flood forms.
 * In Halo: Combat Evolved, the user can perform what players call the "speed pump", or a "slam fire" to use the real-world term. In this method, the player must reload the shotgun almost instantly after firing each shot. After each time he/she repeats this procedure, the shotgun will be reloaded faster than the normal rate. As a result, the shotgun will inflict a seemingly unstoppable barrage of projectiles until there are no longer any shells left to spare. This method is extremely useful in the level, The Library, as well as the remainder of the levels after it.
 * This weapon is easily the best choice in the game for taking out powerful enemies such as groups of Flood Combat Forms, Elites, and Brutes. Even on Halo: Combat Evolved Heroic difficulty, it is possible to take out shielded Elites with as few as two rounds, and only on Legendary do the Flood become capable of surviving a direct hit from the shotgun.
 * Brutes, Councilors and Ultra Elites are the only enemy that can survive a point blank shotgun blast on Normal difficulty in Halo 2. Hunters can be killed by shooting directly into the exposed orange Lekgolo. However, on Legendary difficulty, any rank higher than a Minor Elite's shielding and health can withstand a point blank shotgun blast. Beware, for the Flood can wield shotguns to devastating effect, since they have an extremely long jumping range.

Multiplayer

 * The shotgun's effectiveness in multiplayer games varies depending on the terrain; indoors and in tight spaces, the shotgun is unbeatable, and some consider it superior to the Energy Sword, possibly because there is a slight delay between pressing the trigger and the slash of the sword, while the Shotgun is semi-instantaneous(There's a small gap between muzzle flash, and damaging the target). Most players can utilize this fact to earn a Bulltrue medal relatively easily, though caution should be exercised, as the timing is very difficult to master.
 * Similar to the above, the speed-pump can also be used in Halo: Combat Evolved ' s multiplayer matches.
 * The Shotgun can finish enemies off safely and quickly by shooting them at a decently close range, then striking them with a melee attack immediately afterward, guaranteeing an instant kill.
 * It is best to carry a Battle Rifle with you, or some other medium to long range weapon. If not, have a teammate with you who will have one. On the maps Snowbound and Epitaph, many people prefer to wait by shield doors, preparing to ambush and instantly kill those who come through. If you're charging at at enemy while firing your Assault Rifle hoping to finish him off with a melee attack, and the enemy is charging at you but not firing, chances are he has a shotgun and plans to surprise you with it when you get within killing range, so be cautious.