Squaddie:
Suppression - Fire a barrage that pins down targets in an area, granting reaction fire against them if they move, and imposing a -50 penalty to the targets' aim.

Corporal:
Holo Targeting - Any directed primary weapon shot, hit or miss, will mark the target, increasing your squad's aim by +15 against this target.
Flush - Fire a shot that encourages enemies to move. +30 aim. -50% base weapon damage. Uses 2 ammo.

Sergeant:
Shredder Ammo - Applies +1/+2/+3 Rupture damage with your primary weapon targets based on weapon tech level.
Opportunist - Eliminates the Aim penalty on reaction shots, and allows reaction shots to cause critical hits.

Lieutenant:
Collateral Damage - Area of effect attack that destroys most cover. 3 ammo.
Ready for Anything - If you fire without taking any other costly action, you automatically enter Overwatch at the end of your turn.

Captain:
Double Tap - Allows you to perform an extra attack if you remain stationary for the turn. Does not include the use of grenades or rockets.
Rapid Reaction - If on Overwatch, confers a bonus reaction shot (to a maximum three shots total) for every reaction shot that is a hit.

Major:
Danger Zone - Increases area of effect of Suppression and explosives. +2 explosive radius. +3 suppression radius.
Fire Superiority - While suppressing, you will take an additional reaction fire shot at your Suppression target if they perform an attack, and against enemies who attack a friendly unit within 3 tiles of you.

Colonel:
Saturation Fire - Fire a cone shaped barrage of bullets at every enemy in an area. In addition, the cover of those enemies can be damaged or destroyed. Uses a lot of ammunition.
Iron Curtain - Area of effect attack that deals very little damage but staggers targets, reducing their action points by 1 on their next turn. 3 ammo. 5 turn cooldown.

Sergeant GTS (All Soldiers):
Brace - As a single action that ends a soldier’s turn, assist an adjacent Gunner, reloading their primary weapon and allowing them to fire an HMG after moving with a -10 aim penalty.

Captain GTS:
Suppressing Fire - Firing at or suppressing an enemy applies a -5 stacking aim penalty on them for 1 turn.