Mass Effect Skills And Abilities
There are a couple dozen skills to choose from in Mass Effect. We'll describe the bulk of them here for your perusal.
Combat Skills
Pistols
Increases damage and accuracy while you shoot. Pistols are fine weapons for the characters that can train them: they fire rapidly and with a fair amount of precision, even at medium range, and they seem to lose accuracy while moving slower than assault rifles do. You have to click your trigger for each individual shot, but you'll still likely fire more accurately than your assault rifle-wielding friends, especially if you have to snap off a large number of shots.
Marksman: While the Marksman ability is active, your accuracy will be increased by 60% and your rate of fire will be increased by 1 to 2 shots per second. The rate of overheating on your weapon will decrease to compensate for the increased rate of fire.
Shotguns
Increases accuracy and damage while firing shotguns. Shotguns are best used for close-up encounters, since their rate of fire and accuracy aren't the best, although their Carnage ability essentially turns them into rocket launchers in the hands of an expert.
Carnage: Adds a large splash damage effect to your shotgun blast, causing an increase of 50% to 150% of weapon damage in an area around where you hit. Fire this at the center enemy in a group to dish out the hurt to everyone nearby.
Assault Rifles
Increases damage and accuracy. Assault rifles are fine weapons for soldiers and some of the NPCs; they fire rapidly and have decent accuracy. Stabilize the fire and add a heat sink to let yourself fire more rapidly, and remember to fire in bursts to avoid overheating your weapon.
It's worth pointing out that assault rifles are difficult to use early on in the game; every one that you find up until level 20 or so will have a 1 rating for accuracy (out of 100 or so). This makes them frustratingly difficult to fire at long ranges or for more than a couple seconds at a time. To counteract the accuracy problems, try to fire from a kneeling position (which helps your aim), and fire bursts of a couple seconds in a row to hit distant targets.
Overkill: Overkill allows you to fire more rapidly for a short period of time, during which you'll lose accuracy less slowly. (This doesn't make you more accurate, necessarily; it simply prevents your fire from spreading out from the target zone as quickly.) Great for spraying down multiple enemies or attempting to take down a single distant target.
Sniper Rifles
Increases damage and accuracy with sniper rifles. Without some amount of training, sniper rifles will be basically unusable by your character, as you won't be able to even zoom in. In the hands of a well-trained character, though, sniper rifles are great for taking down distant foes.
If your main character can't use sniper rifles, we wouldn't recommend training any of your followers in their use. Doing so will let them hit distant enemies, sure, but in most cases your foes will come towards you when you engage them, forcing you to switch your teammate's weapon. If you're in the habit of rushing forward in front of your teammates, then they might be able to support you from the rear, but a better strategy might be to train yourself in sniper rifles and use your team commands to send your team forward to intercept the enemies as they come for you. Of course, in most interior fighting, sniper rifles will be a bit unwieldy to use, so be sure to have another weapon skill to fall back on.
Assassination: Assassination lets you greatly increase the amount of damage that you deal with a single shot from your sniper rifle. While there aren't a lot of bosses in Mass Effect for you to use this on, it can still come in handy when you're attempting to take down oversized foes like Geth Primes.
Basic Armor
Basic armor is the basic armor talent for weaker characters, like Adepts. It allows you to wear light armor, but not medium or heavy armor. Increasing your skill here will increase the amount of damage reduction that your armor provides you, as well as the "hardening" effect, which…well, we have no clue what it does, but presumably it's favorable to you.
Shield Boost: Activating shield boost will recharge your shields very quickly, preventing you from having to wait for them to recharge naturally. You'll have to wait 45 seconds in between using the ability, but still, it'll greatly increase the amount of time that your shields are active and protecting you during battle.
Tactical Armor
The same as Basic Armor and Combat Armor, but Tactical Armor will usually let you start off wielding basic body armor and eventually unlock medium armor.
Shield Boost: Activating shield boost will recharge your shields very quickly, preventing you from having to wait for them to recharge naturally. You'll have to wait 45 seconds in between using the ability, but still, it'll greatly increase the amount of time that your shields are active and protecting you during battle.
Combat Armor
Combat armor is for soldiers and characters capable of wearing the medium and heavy armors. The lower ranks will let you wear medium armor, but as you increase your skill, you'll unlock the ability to wear heavy armor.
Shield Boost: The effects of shield boost are the same as the Basic Armor skill. It's more important to get high ranks of Shield Boost when you have Combat Armor, though, as the amount of shielding you have will be proportionally greater than your light armor-wearing compatriots.
Assault Training
Assault training will increase your weapon damage by one percent per point applied. It's a decent bonus, but one you'll want to start taking only after you've maxed out your weapon skill, which also adds accuracy. The secondary bonus here adds to weapon melee damage. It'll be useful if you enjoy whacking enemies in combat, but it won't be very much use if applied to a follower, since they'll rarely partake in melee combat.
Adrenaline Burst: Activating this power will immediately reduce the cooldown on all your other abilities, allowing them to be used again. This is more useful for Vanguards than Soldiers, since you'll have biotic skills that you can use repeatedly, but even Soldiers may sometimes need to activate Immunity or Shield Boost in rapid succession.
Fitness
Fitness offers up a basic health boost. The first point of fitness will net you a flat 10% bonus to your health, but after that it'll only be giving you 4% or fewer health per point. Health bonuses aren't as necessary as they may seem; playing carefully will generally allow you to get through combat while only taking shield damage. We'd recommend getting this up to the point where you can unlock the first rank of Immunity and then stopping.
Immunity: This power will increase the amount of protection you have from damage for a short period of time. At first, it'll offer you 50% damage immunity for 10 seconds, a very appreciable number. If you manage to max out the skill, though, you can reduce the damage you take by 80% for 20 seconds, with a recharge time of 30 seconds, meaning that you can be almost unkillable almost all the time. This is a great skill to max if you intend to use melee attacks a lot, but otherwise it's merely a safety net if your shields go down while your First Aid is on cooldown.
