The Ranger is one of the 3 primary shooter classes. Rangers specialize at finishing off wounded enemies. While Sharpshooters can do more damage, Rangers take more shots, and thus can split damage across multiple targets. It is not rare for a Ranger to kill 2 enemies after your other soldiers have exposed and wounded them. The Ranger can also be spec’ed to protect your squad with overwatch shots, and equipped to shred or burn enemies. Nothing the Ranger does is unique. But the Ranger is uniquely good at doing it.
Cool Under Pressure
With this ability the Ranger gets to move twice and still overwatch. Doesn’t sound significant. I didn’t even consider taking this ability until I saw other players use it. Ever Vigilant vastly improves the Rangers action economy. The value is obvious on timed missions, but it also prevents the Ranger from falling behind the squad, and when the Ranger does end up out of position, it allows him to move all the way across the battlefield and still contribute on that turn. One important caveat: Several ancillary actions will cancel Ever Vigilant, such as opening doors, reloading, or picking up loot.
Alternatives: Walk Fire or Close and Personal.
Walk Fire eventually becomes obsolete and is rarely a better option than just shooting.
Close and Personal is okay, but it is often overkill, as Both Barrels kills most everything, and the Ranger isn’t usually that close to the enemy for this ability to matter when shooting with a rifle.
This is a quintessentially Ranger ability, and it is very good. The Ranger will be shooting at the same target quite a bit, and adding +10 aim is exactly the kind of perk you want on a shooter class. Overwatch shots will activate Locked On. This ability becomes even more valuable if you choose Rapid Fire at Gunnery Sgt. rank, which you should.
Alternatives: Pump Action or Covering Fire.
Pump Action will rarely be useful, as the Ranger does not get in close as often as the Assault, mostly preferring to shoot twice rather than moving up. Also in the late game, Rapid Fire becomes almost as deadly as Both Barrels.
Covering Fire only provides a slight aim penalty to the target, and sometimes it causes the Ranger to miss a good overwatch shot, by triggering on an enemy shooting from cover, rather than a wide open runner. The most common overwatch fire is on activating pods, and here Covering Fire does nothing.
Cool Under Pressure:
I used to believe that this ability should only be taken if you also intended to take Rapid Reaction at Gunnery Sgt. rank. Which would maximize the utility of both. When I moved away from Rapid Reaction, I also temporarily moved away from this skill. Now I feel that was a mistake. Even if you don’t get that beautiful synergy with Rapid Reaction, Cool Under Pressure is a great skill, and with Ever Vigilant my Rangers end up overwatching quite frequently.
Here is what I wrote about Cool Under Pressure for the Gunner build guide:
In LW2, unlike LW, incoming enemies can shoot you. That is, unless you shoot them first with an overwatch shot. Good overwatching is incredibly valuable as a defensive measure. Some of the worst hits I take are from incoming enemies that have flanking shots on my soldiers. Shinobi scouting is one way to prevent this, but your scout can’t be everywhere. The next best thing you can do is have a soldier that specializes in overwatching to protect your squad. Cool Under Pressure adds +10 aim on reaction shots, thus improving your chance to shut down enemy activation fire. Additionally it enables critical hits on overwatch shots, resulting in outright kills much of the time.
Alternatives: Aggression or Center Mass.
Aggression is good. It grants some additional crit chance, very useful when targeting exposed enemies.
Center Mass is very good. Rifles have lower base damage than other primary weapons, and Rangers shoot a lot. Taking Center Mass over Cool Under Pressure is not a bad choice. It would be trading some defense for a bit more offense.
This is another core perk for Rangers, the designated finisher. It is very good, not quite great; an obvious choice when matched against the alternatives.
Alternatives: Fortify or Suppression.
Fortify is just okay.
Suppression is just okay. You don’t have the ammo for it, nor many of the helpful Gunner perks, and by this stage in the campaign it is weak compared to other forms of control. The Ranger needs to be killing, not suppressing. If you want Suppression take a Gunner.
Just like Ever Vigilant this is another action economy ability I never would have selected had I not seen another player using it. Implacable must be seen in practice to be properly understood and appreciated. For example, after putting the Ranger in a dangerous position to get a flank, implacable will allow the Ranger to pull back to safety. Or if the Ranger can finish off an enemy with the first shot, a free move can then give the Ranger a better shot on the next target. During combat, Rangers want to use both their actions for shooting, rather than moving; Implacable allows them to do exactly that, and still relocate if desired.
Alternatives: Bring’Em On or Grazing Fire.
Bring’Em On is very good, but after getting Rapid Fire at Gunnery Sgt. rank, this ability is likely to be overkill in those situations it actually procs, such as when shooting flanked enemies. Still, there are numerous late game enemies with high dodge, or high defense, or high HP. More offense is always needed, and this is solid pick at this rank.
Grazing Fire is not good this late in the campaign. Its utility diminishes as aim improves, and is less relevant for Rangers, given all their bonuses to hit.
This is the Ranger’s class defining ability. Before Gunnery rank, the Ranger was mostly a finisher. With Rapid Fire the Ranger is a finisher, a burner, a flat out murderer. Rapid Fire has enormous synergy with both Locked On, Executioner, and special ammunition. With Dragon Rounds you get 3 chances to light your target on fire! Even after running dry, this Ranger can reload with the first action and then shoot twice.
Alternatives: Tactical Sense or Rapid Reaction.
Tactical Sense is great, but not nearly as good as the other 2 choices.
Rapid Reaction is fantastic. In fact it is so brutal that when it procs it will trivialize many encounters. Only the most dangerous pods can endure a full Rapid Reaction overwatch and still present a threat to your squad. Even if it only adds 1 extra shot on average, it is an amazing ability, weakening incoming enemies, and disabling their activation fire. So, why choose Rapid Fire over Rapid Reaction? Well, once upon a time I had an A-Team squad of 8 soldiers fighting a pitched battle on a Supply Raid mission. There we are, in good defensive position, my shooters on a cliff, the assault too far forward, maybe one soldier has a scratch, only about 3 enemies active. I had been fighting continuously for many turns, activating one pod after another, but managing to keep it under control... And then the command pod comes over the train, right on my flank. Everything goes to hell. On this critical turn my Rapid Reaction Ranger was in good position but without ammo. He spent one action reloading and the second action was overwatching. What else could he have done? shoot once? A MEC predictably rocketed the Ranger breaking the overwatch, and splitting me open like a cracked egg. The squad wiped, and I quit the campaign. I dissected this encounter like no other, reevaluating all my tactical decisions, squad composition, and every class build. I decided that my principle mistakes were leaving my flank open! over-extending! and awakening the command pod! A lesser revelation was that Reaction Fire Rangers are not very good in a prolonged fight. Yes, they are incredible openers, but what about when the fight spans 3 or more turns? They can potentially take more total shots; a possible 4 instead of 3. But it means you must leave at least 3 enemies alive and mobile, and those enemies must cooperate with your plan, running from cover rather than just shooting. There are a lot of ways that this can backfire. Some enemies have Shadowstep, others high dodge, others high innate defense. Codices can teleport instead of running, then disable your overwatch with a psi bomb. Gunners can suppress you. They can get lucky and run through high cover… and of course MECs can rocket you.
My conclusion is simple. Additional directed shots are much better than potential reaction shots. You should not trade one for the other.
This ability will marginally improve all your stats, which is good.
Alternatives: Rupture or Kill Zone.
Rupture is usually a bit weaker than Rapid Fire. It uses more ammo, has a slightly tighter expected damage range, and ruptures the target. Not sufficiently better that Rapid Fire in any situation.
Kill Zone: Here is what I wrote about this ability in the Gunner class build guide:
Kill Zone does not work as you would expect when you are in concealment. Nor does it trigger as consistently as Suppression, requiring that the enemy move at least 2 tiles within the Kill Zone area of effect. I have been very frustrated with this ability not triggering when I expected it to, and have abandoned it completely, preferring instead to use suppression, which is very similar in effect.