The simple answer to the question is Tactical. I'll explain why, so keep reading.
First, I'd like to state for the record that you can be successful, enjoy the game and all it's content with any career path. This article is just my answer to the question of: "Which is the most effective?"
I'd like to lay out the various Career Paths for comparison. You can decide for yourself based upon the abilities each one provides, but I've come to the conclusion that Tactical is truly the best choice, in general.
There are 3 Career Paths a player may choose from: Tactical, Engineer, and Science.
- Captain Space Abilities: Attack Pattern Alpha, Tactical Fleet, Fire on My Mark and Tactical Initiative
- Captain Ground Abilities: Tactical Initiative, Target Optics, Strike Team, Fire on My Mark, and Security Escort
- Known for direct DPS ability in Space and Ground maps.
- Tactical Captains have the best DPS potential in the game, in both space and ground maps.
- Captain Space Abilities: EPS Power Transfer, Nadion Inversion, Miracle Worker, and Rotate Shield Frequency
- Captain Ground Abilities: Engineering Proficiency, Support Drone, Cover Shield, Orbital Strike, and Reroute Power to Shields
- Known for Tanking/Healing ability in Space and Fabrications/Generators/Mines on Ground maps.
- Engineers are typically the "tankiest" players in the game, in both space and ground maps.
- Captain Space Abilities: Science Fleet, Scattering Field, Photonic Fleet, Sensor Scan, and Subnucleonic Beam.
- Captain Ground Abilities: Dampening Field, Nanoprobe Infestation, Neural Neutralizer, and Scientific Aptitude
- Known for Healing/Science-based ability bonuses (Examples: Flow Capacitors or Gravity well) and CC (Crowd Control) abilities on Ground Maps.
- Science Captains are generally considered the best pure healers in the game and the best Debuffers.
Engineer: On ground missions, Engineers create (mostly) stationary pets, some of which are defensive and others offensive. They also specialize in shield healing on ground. They can be extremely effective and are the easiest for poorly-geared or inexperienced players to use, IF the player actually sets up mines, health/shield generators, and turrets. The Engineer should then attack the enemies from within the healing radius of the generators, force the enemies to travel over the mines to reach the Engineer, and get additional support from their support drone and turrets. Of course, you can get pretty much the same benefit from your away team having Engineers, rather than YOU being an Engineer. Because of the generators healing hit points and shields and reducing shield damage taken, combined with the engineer's innate shield-healing abilities, the Engineer is generally the most durable character on Ground, but he is basically stationary. In PvE, they are extremely formidable on ground and many players prefer Mines over Grenades because enemies tend to run out of the grenade radius, but they take absolutely NO steps to avoid mines. This is a significant advantage to Engineers.
In space missions, Engineers really specialize in energy weapons. They get EPS Power Transfer and Nadion Inversion. Both have the effect of negating power loss, due to both leeching/draining AND energy weapon use - ie weapon power consumption when you fire. Yes, that means they can shoot weapons at nearly full weapon power most of the time, except for long encounters where they would have about a minute where the 2 abilities are on CD (Cool Down) before they could use EPS or Nadion a second time. Basically, this provides stable and reasonably good damage output. Of course, Engineers have a career-specific hull heal, shield heal, and resistance buff. So, this can help in a pinch - for those times that you might be taking a ridiculous amount of damage. This is why they are thought to be the best "tanks" in the game.
Scientist: On ground, Sci Capts are excellent at healing hit points. In fact, they are the only career path that has specific direct hit point-healing abilities that can be used on other players. They also have CC (Crowd control) with Anesthizine Gas grenades and ranged AOE (Area of Effect) damage abilities like Exothermic Induction Field. They can be very mobile, heal themselves, provide CC, and offer AOE damage. To compare to a fantasy MMO, they are like Mages with great healing abilities too. Many feel that Science is the best way to do ground combat. Truthfully, depending on the situation, they can be.
In space missions, Sci Capts get very few abilities that help their damage. They do get Photonic Fleet, which is nice, but not anywhere close to overpowering. It also has a long CD. They also get Subnucleonic Beam, which strips buffs from a target - very handy in PvP, but not so much when there are 10 other enemies you need to kill. The same goes for Sensor Scan, which reduces the resistances of you current target, but not all targets. Basically, Sci Capts can be really effective against a single target, which isn't to say they can't use Fire at Will or Gravity Well, but they can't apply buffs to their damage the way an Engineer (And, certainly, a Tac Capt) can. They focus on debuffing specific targets, not generally buffing their own out-going damage. However, Sci Capts do get access to certain traits and abilities that help them to deal a little more damage with Gravity Well and other exotic particle damage forms. As a result, they generally have the highest damage from Gravity Well. That's definitely good, but not awe-inspiring when you consider that Gravity well has almost a minute CD and Tacs and Engis can use a little less powerful Gravity Well themselves. In general, you can do good enough damage to kill things, but Sci has the lowest damage potential.
Tactical: On ground, Tac Capts benefit from multiple weapon damage buffs. They get these from their career path kits and from inherent captain abilities. It is common to crit/flank with a powerful sniper rifle for well over 1,000 damage from a single shot. In fact, I've seen 4200 on a single shot with a Tac. How? By using multiple, stacking damage buffs. Engineers and Scientists don't see that kind of damage, even with the best gear. They don't have the ability to buff their damage the way a Tac can. Tacs also can lead off with a massive Grenade to significantly injure or even kill multiple enemies. But, Tacs are also believed to be glass cannons on the ground - with good reason. Tacs do not get any true "heals" for shields or hit points. It is for this reason, it's difficult for new players to be good with Tacs on the ground. However, once you get elite gear and you get enough abilities that provide healing over time in addition to buffing your damage, such as Rally Cry and certain reputation traits, you are able to heal well enough to survive. You take cover to let your shields recharge, instead of casting a heal on them. Once you've built/geared the character up, a Tac Capt can do tremendous damage and can be surprisingly durable, but not as tough as the other 2 careers. Unlike an Engineer, they can't heal shields or drop fabrications/generators. Engineers set mines and pull enemies such that they run over the mines, whereas Tacs lead off with a grenade and don't have to "pull" enemies. They literally heal by shooting more. This means Tac Capts are more mobile and will continue to shoot when Engineers would stop to heal their shield or drop a new generator. While Sci Capts can lead off with gas grenades or exothermic induction and heal themselves on the move, which allows them to be mobile and durable, they don't get anything that directly buffs their damage and they don't get pets that add to their damage, like an Engineer, but Tac Capts get massive damage bonuses. A skilled Tactical player can avoid being overwhelmed by using line of sight to his advantage and simply drop single targets in a mere moment, then rinse/repeat for the remainder of the enemies. A skilled player with access to the best gear, will be able to do amazing things with a Tactical Captain that the other other career Paths simply cannot do on the ground, but until a player reaches a certain level of skill and gear, it's harder to survive on the ground.
In space, Tac Capts don't just do more damage, they do a LOT more damage. There are people that will argue with me bitterly about this and they honestly think they do just as much damage with their Science or Engineer captains. But, if they took the exact same weapons/abilities, whether it's Torpedos with Gravity Well or Beams with Fire at Will or Polaron weapons with high flow capacitors skill, the Tactical Captain would do more damage. Why? Attack Pattern Alpha. (APA) The Tactical counter to a Science Captain's "Sensor Scan" is "Fire on my Mark," which is actually better. The counter to any bonuses to Gravity Well is that Gravity Well should NEVER be close to the majority of your damage - if it is, you're under-utilizing your weapons and missing out on damage. Science has no Counter to APA. You can use Gravity Well and Plasmonic Leech on a Tac Capt, and the result, when you use APA, is that the weapons damage is so much larger than the potential of the Gravity well that the damage increase from APA is insurmountable. Engineering Captains do get to fire at max weapon power quite a bit, but with various abilities that buff weapon power levels and increase the regen of the power level, what Engineers get does not come anywhere close to what APA provides in terms of damage output. In space combat, NOTHING beats a Tactical Captain in DPS and it's a wide margin.
At the top, I stated Tactical is the best Career Path and, now that we have some understanding of what the 3 paths offer, we can have some reference as we explore the reasons why I claim Tactical is best overall. Tactical is the best, not just the best DPS or my personal favorite - it is THE best career path choice.
So, why is Tactical the best?
- Attack Pattern Alpha - Nothing, and I mean NOTHING, impacts DPS more than APA. I could expound on exactly how and why, but that pretty much sums it up.
- This game's current content is based on DPS - There is no true raid content and certainly none that requires TRUE Raid-Tanks or Healers. The "holy trinity" of MMO gaming doesn't translate to this game because of how high damage can scale. Damage is over-emphasized. Even though I think the developers did not intend for this situation, it is the reality.
- Tanks are, essentially, just lower DPS - Tanks typically won't have aggro because their DPS is too low, so all those extra resistances and shields are virtually useless. If you don't have aggro, you're not tanking - you're just doing lower DPS. In fact, both Engineers and Science Captains get some nice, clickable resistance buffs with long CDs (Cool Downs), but that doesn't matter if you don't have aggro anyway. Instead, higher DPS characters (typically well-geared Tac Capts) are forced to tank enemies and the "tank" players are simply destined to be the last ones to die. It's because of this that tanks are viewed in some circles as more selfish players or low-skill players, even though they may be very skilled and their intent is most likely to be helpful to others, not to be selfish. The feeling is that Low-DPS players are being carried by High-DPS players and, truthfully, that it is exactly what's happening. At some point, the game boils down to whether you're Low-DPS or High-DPS.
- If you actually want to try to tank, Tactical is the only one that can hold aggro -When an equivalently geared Tactical Captain uses APA (Attack Pattern Alpha), there is no hope of either of the other two careers being able to hold or take aggro from him. There is really nothing an Engineer can do that will give him enough damage/threat to take enemies off of a Tactical Captain who uses APA at the beginning of the fight. (On top of that, there's Tactical Fleet and Fire on my Mark, as if APA wasn't enough.) Because of the combination of APA, Fire on my Mark, and Tactical Fleet, Tactical Captains can produce much more than double the damage of the other two career paths for about a 30 second window. On Normal and even Advanced Difficulty, that is usually enough to kill the enemies. If you want to hold aggro, you MUST have APA.
- Engineering and Science Captains aren't significantly tougher or better healers than Tactical Captains - I know what you must be thinking: "Engineers get Miracle Worker. How can they not be significantly better?!?" The answer? Engineers can use MW (Miracle Worker) once every 4 minutes, unless they waste a trait and then they can use Miracle Worker twice in 4 minutes. Compare that to Engineering team 3, which can be used every 15 seconds if you have a copy of it OR 2 purple Maintenance Engineer DOFFs (Or, 3 blue DOFFs) on active duty for space. If we're honest with ourselves, MW has such a long CD and using a Trait to give you an extra use once every 4 minutes is such a waste that you can't say MW is a significant healing benefit. Engineers also get Rotate Shield Frequency, which slowly heals their own shields a little bit and increases hardness of the shields - but that is self only and doesn't improve their ability to heal other players. Science Capts get Science Fleet, which is nice to slightly buff the 2 healing skills and make the Sci Capt's shields a little tougher, but that is not significant enough a benefit to make them so over-powering that you can't heal yourself or others as a Tactical Captain. Science Fleet results in such a small amount of additional healing that it isn't overpowering - and that's only while the buff is active! It's barely noticeable.
- If you want to be "tanky," then get a tanky ship and multiple healing abilities - There is no rule that says Tactical Captains can't max Shield Emitters skill or that they can't have Engineering Team. There is nothing that says Tactical Captains can't have all the same BOFF (Bridge Officer) healing abilities as the other 2 career paths. There is no rule that says Tactical Captains can't fly a Cruiser or Carrier. Basically, if you want/need survivability, get a ship with high Shield Modifier, high Hull, and Masteries that give Hull/Resistance. (Like a Tal Shiar Adapted Battle Cruiser.) You can have multiple ships, each for a specific purpose. One could be for soloing, one for STFs (Special Task Forces), and another to truly maximize DPS. There is no reason Tactical Captains have to be glass cannons or depend on others for healing. If you CHOOSE to do that, that's up to you. But, there are only so many offensive abilities that you can use at the same time - so what are you going to use the rest of your BOFF stations/abilities for? Eng Team, Sci Team, Transfer Shield Strength, Emergency Power to Shields, Auxiliary to Structural, etc. I'm sure you get the point - you can be durable and able to self-heal as a Tac. It comes back to the question: can you use APA as anything other than a Tac Capt? APA is the ultimate trump card in STO and it belongs to Tactical Captains.