This build is very similar to the Soldier / Shock Trooper build. A variety of combat and biotic talents add to your survivability with Pistols and Shotguns as your primary weapons. The Shock Trooper specialization improves the Barrier and Adrenaline Burst skills. The playstyle is similar to a tank. Most of the talents you have increase your survivability with just a few talents for increasing damage.
Specialization: Shock Trooper
8 Pistols (unlocks Shotguns and Marksman (skill))
12 Shotguns (unlocks Carnage (skill))
12 Assault Training (unlocks Tactical Armor and Adrenaline Burst (skill))
12 Tactical Armor (unlocks Shield Boost (skill))
8 Throw (unlocks Lift and Throw (skill))
0 Lift (unlocks Lift (skill))
4 Warp (unlocks Barrier and Warp (skill))
12 Barrier (unlocks Barrier (skill))
12 Vanguard / Shock Trooper
12 Spectre Training (unlocks Unity (skill))
12 Charm or Intimidate
Tactical Armor, Barrier, Soldier / Shock Trooper, and Spectre Training all provide bonuses to survivability, mostly in the form of increased health. Throw is more of an offensive talent, but does indirectly help survivability by throwing enemies into walls are the ground. These talents should be enough to keep you alive while you blast things with shotguns.
Warp doesn’t provide any survivability but is a requirement to unlock Barrier. It’s not that bad of a talent but with so few points, it just won’t be that effective. It doesn’t mesh very well with the other talents.
None of the bonus talents really improve this build, but there are a few bonus talents that you can use in place of some of the class talents as alternatives. Find them in the Variations section below.
The basic idea is to stay in close range at all times but still stay alive. Use Barrier to boost your shields. If it wears off or the enemies push through it with damage, use Shield Boost to refresh your shields to full (including the Barrier). Throw can also be used for survivability, but it can be hard to hit more than one enemy.
In between those skills you should activate Carnage, so you can hopefully kill everything before the protection skills wear off. If all those skills go on cooldown, you can finally use Adrenaline Burst to reset all of them. If you can hold out until Carnage is used up, all the better, but Adrenaline Burst is preferably used to reset your defensive skills. Pistols with Marksman should only be used when you are forced to fight at range.
Normal enemies will usually go down before all your skills are on cooldown, but bosses are usually a lot tougher. You may need to rely on squad member skills to disable enemies while your skills are on cooldown. If the whole squad’s skills are on cooldown, you will just have to hide behind a barrier and wait.
Warp with only 4 ranks won’t be very strong. It will increase your weapon damage for a short time and does a little bit of damage over time, but the bonuses aren’t good enough to use it over the other skills. Only use it if your other skills are on cooldown or if you don’t need to use any defensive skills at the moment.
More Pistol ranks instead of Barrier ranks – You can sacrifice a few talent points in Barrier to get a higher Pistol rank. You will be able to snipe medium distance enemies a bit better. Up close “shotgunning” is still best option for damage and stopping power though. Pistols should still only be used when you have to.
Assault Rifles instead of Shotguns – Assault Rifles are one bonus talent that can work well with this build. They are pretty good all around, but especially in short range just like Shotguns. Later Assault Rifles with good upgrades can do well at medium range, but they are best in close range when all of the bullets will hit.
Singularity instead of Throw – Singularity is a good alternative to Throw. Throw is best against single targets, but Singularity is best against groups. It will immobilize enemies in a pretty good size area and is really good as a trap to block off a choke point. Any enemies that come through get immobilized giving you free shots for a while. Enemies afflicted by it can’t fight back either, so just like Throw you will gain some survivability.