I have a little bit of a vested interest in understanding how skills work, so I figured I would write down what I know, and what I can guess, and see what others know and can guess. This is not about Bridge Officer skills, which I consider abilities, nor is this about abilities that you get while leveling. this is going to be boring for most of you.
STO Captain Skill Basics
A character skill adjusts how well you do something, not if you can do something (the only exception is the ability to train your BOffs with specific abilities, but blah). Every skill has a rank and cost per level. The rank is what rank you have to be to access the skill, and the cost per level is how many skill points it costs to level up that skill. All skills in the same rank have the same skill cost. Skills can be level 0-9.
As you gain levels in a skill, the value of that skill goes up. All skills in a rank share the same progression, rank 1 has a unique progression, rank 2 has a unique progression, and ranks 3-5 share the same progression (which will make sense in a bit). Traits selected during character creation can increase the value of the skill. This is a flat amount.
Rank 1: 6,10,12,14,15,16,17,17.5,18
Rank 2: 8,14,18,22,24,26,28,29,30
Rank 3-5: 10,18,24,30,36,40,44,48,52
As you can see, there is a diminishing return on the value of a skill as the level goes up. For ranks 1 and 2, it is a curve, with 4 or 7 being considered optimal. For ranks 3-5 it flattens out at level 5 and above, with level 4 being the optimal. Optimal is in the eye of the beholder, so this is just my observation. Also note that if you add up all of the values of the max, it adds up to 100... this will be important later.
STO Captain Skill Influence
So now we know what skills are, and that they only effect how well you do something. So, what skills apply to what abilities? We know that all skills are divided into Space and Ground, so that quickly divides what the skill influence. I have heard rumors that some ground abilities effect space, but i can't find anything to back that up. for right now, I am going to focus on space abilities.
What we know:
Every Starship "can" be influenced by up to three skills. Starship Command will influence every single ship you fly and is a rank 1 skill. Cruiser Captain will influence all cruisers you fly and is a rank 2 skill. Heavy Cruiser Captian will only influence your abilities in a Heavy Cruiser, not in any other ship, and is a rank 3 skill. In fact, for Starfleet Training, and the equivalent KDF Training, the rank 1 skill is universal, the rank 2 skill divides the ships into three groups, and then the ranks 3-5 skills are specific to that exact ship. So a maximum of three skills, one from each grouping, will ever influence your ship.
Every weapon you mount on the ship has one of two rank 1 skills that will influence it. Either Starship Energy or Starship Projectile Weapons Training. Energy is things like phasers or disruptors, while projectiles are things like torpedoes and mines. Then for each weapon type, there is a sub division in the rank 2 skills. For energy is it cannon (cannon and turret) vs beam (bank vs dual cannon), and for projectile it is torpedo vs mine. Finally the ranks 3-5 skills are specific damage types of those weapons. So like the starship skills, it appears that all weapons will be influenced by up to three skills. A Rank 1 generic skill, a rank 2 division skill, and a rank 3 specialty skill.
What we can guess:
Based on how the weapon and starship skills work, we can guess that all abilities or things that a skill can influence will have a maximum of three skills that can or will apply to it. A rank 1 generic, a rank 2 division, and a rank 3-5 specific skill. It does not mean that there will always be three skills that apply, for instance, the light cruiser we start with, does the rank 2 cruiser skill apply to it? And there is no rank 3-5 ship skill that will apply to the rank 1 or rank 2 ships, leaving them with at most two skills influencing them.
For the ground skills, I am not sure about some things. In the class specific skill tree, it appears to follow the same pattern as above. A pair of generic rank 1s, some rank 2s that sub divides abilities, and then specialty rank 3-5 abilities that reference specific things only visible in rank 2. BUT... does the officer type abilities only influence the player, or do the Bridge Officer ground abilities also get buffed by these, because if they do, then the bridge oficers get buffed by 4 skills, as there is the generic BOff buffs in the base of the Starfleet/KDF Training branch.
STO Captain Skill Value
So, now we know what a skill is, and what it influences... but what is its value. As you level up, the value of the skill increases, you can see its value in the skill description when you click a skill. That is nice and all, but what does that men, and how do multiple skills that influence a single thing stack?
What we know:
for every weapon, there is three skills that will influence it. A Phaser Turret will have Starship Energy Weapons Training, Starship Cannon Weapons, and Starship Phaser Weapons influencing it. A Disruptor Dual Cannon will have Starship energy Weapons Training, Starship Beam Weapons, and Starship Disruptor Weapons influencing it. A Plasma Mine Launcher will have Starship Projectile Weapons Training, Starship Mines, and Starship Plasma Projectiles influencing it.
Take the value of all three skills, add them together, and you get the skill value applied to that weapon. For weapons, the skill value translates directly to a % increase in damage. So remember how the max ranks from 1, 2 and 3-5 added to 100? That means if you have all three skills that apply to a weapon maxed, the weapon will do +100% damage.
What we can guess:
So for any action or item that is influenced by skills, there is a value range of 0 to 100 that can be applied. The unknown is what does this value mean. For most, i expect it to be a flat % increase in effectiveness, like with the weapons.
some of this is very testable. Create a new Klingon, spend points in the starship skill, see how much the hit points increase per level (and skill value). Some won't be very testable (the bridge officer skills being effected by skills)
anyway... that is what I know about skills... what do you all think?
Dual Cannons are effected by Cannon Skill, not the Beam Skill.
Otherwise, from what I read (cursory read I'm afraid) everything looks accurate.
I am pretty sure that dual cannons are effected by the beam skill, I even remember a dev explaining it that way. a dual canon has the front arc only restriction of a cannon, but the used the beam skills like a bank.
(Energy Weapon Types, most damaging to least all things being equal)
Cannon - Front Slot Only, Escort Only, Cannon Skill
Dual Cannon - Front Slot Only, Beam Skill
Bank - Front or Rear Slot, Beam Skill
Turret - Front or Rear Slot, Cannon Skill