I can pretty well understand the difference between say, a situation that calls for the sniper rifle or the shotgun (one is better at long range, and one at very close range), but in what situations would I want to equip or activate a SMG vs an assault rifle, for instance? What situations are appropriate for using a pistol?
Say, for instance, I see an enemy that's a bit close for a sniper rifle, but not close enough for a shotgun. What weapon do I reach for?
Or in another way of looking at it, if I have a shotgun, is the SMG redundant? They both seem like they would work well in close quarters. Similarly, if I have a SMG, is the Assault Rifle redundant? They're both rapid-fire weapons.
In what ways does each class of weapon excel? How should I choose between them (either in my loadout or in the heat of battle) based on the mission or the enemies/situations I will encounter?
Best Answer
A lot of this is dependent on class. As a Vanguard for example, you'll probably never want to use an Assault Rifle - they're just too heavy, and as a Soldier, you'll usually give SMG's a pass - everything they can do an AR does better. Meanwhile, an Infiltrator gets lots of bonuses when using their trusty Sniper Rifle, evening if irresponsibly shooting it from the hip.
The second consideration is range: at very long ranges, a Sniper Rifle offers top notch accuracy. AR's and Pistols Can be pretty good. SMG's can be flaky though, and shotguns are nigh useless. By contrast, Shotgubs ate devastating at short range, but the loss of peripheral vision while looking down that sniper scope can get you killed.
The next consideration is the defenses of your opponents. Slow firing, high caliber weapons like Sniper Rifles and Pistols chew through Armor, but are weak against Biotic Barriers and Shields. Rapid fire weapons with a lot of projectiles, by contrast, like SMG's and Shotguns chew up Shields and Barriers quickly, but have trouble with armor. Assault Rufles are a bit of an odd duck as they're 'pretty good' at handling everything.
Additionally there are mods availiable for several weapon types that alter their capabilities. You can add Armor-penetration to an SMG or a shotgun, or a melee upgrade to a pistol or shotgun. Maybe a scope on your SMG to improve its mid-long range performance?
Finally, you may want to pair some weapons up with certain specialty ammo. For instance, SMG's are devestating in combination with Cryo or Incendiary Ammo as their high rate of fire gives them more opportunities to proc the special effects provided by these ammo types than, say, a slow firing shotgun.