Disclaimer:
Why is this not in Players Helping Players or Player Guides forum?
Because I could be totally wrong about everything, its mostly theory building and personal observation.
< Companion Basics >Armor
- Light: Increases healing done by 1-7% and reduces the cooldown of Break Free by 5-35%. Epic provide 900 armor.
- Medium: Increases damage done by 1-7% and reduces the cooldown of Roll Dodge by 5-35%. Epic provide 1900 armor.
- Heavy: Increases healing received by 1-7% and increases the amount of damage blocked by 1-7%. Epic and shield provide 2900 armor.
- Maximum Armor rating a companion can achieve is 23,200 with 7 Epic heavy armor and a shield.
- Restoration staff ability Combat Prayer can add Minor Resolve to companions for an additional 2974 armor.
In order to level an armor type on a companion they must wear at least 5 pieces to gain experience with that armor type. While you can mix-match if you want to, they won't gain any experience with any armor type unless they have 5 of the same equipped.
Weapons
- Tank: One-Hand and Shield or Frost Staff.
- Melee: Sword, Axe, Mace, or Dagger; Two-Handed or Dual-Wield.
- Ranged: Bow, Restoration Staff, Flame Staff, or Lightning Staff.
In the case of melee weapons, the type used does not affect their damage or status effects as they are all the same. Having a companion with Dual-Wield Daggers has no difference than using a Sword, Axe, or Mace; only the appearance is different.
Ability Damage Calculation
The formula for what I name Base Power
For a level 20 Companion:
Base Power = 1.5 x tooltip Weapon Damage + 3000
A LA without racial or other Damage Buffs and before Armor Resistance is then for a twohanded purple weapon:
Damage = 1.5 x 900 + 3000 = 4350
And for example the Damage Shield of Bastian is then also 4350, that same base power.
Abilities are in general a factor times that base power:
For example Sniping Silver Damage is 2*BP and with for example two handed purple without buffs 8700
With S&B and a purple sword (weapon damage 450) the BP becomes 1.5*450 + 3000 = 3675 and Sniping Silver 7350
(and with for example the 3% damage buff of Bastian for purple S&B the damage is 1.03*7350 = 7571
The same math for white, green, blue weapons with 600,700,800 as weapon damage (or 300,350,400, for S&B and DW)
That 3000 is companion level related (NOT weapon related) and from my notes the formula is:
Lvl Comp * 75 + 1500
At level 20 this becomes 3000.
Health buffs like Vigorous do not change those values.
Roll Dodge
Roll Dodge is the highest prioritized action the companion will perform above all else and have two charges, base cooldown is 8 seconds while with 7 Medium armor equipped reduces it to 5.2 seconds. When they Roll Dodge is dependent on what weapons they have equipped.
- Tank weapons will not Roll Dodge until they are critical =< 25% health and the target they are focused on attacking is close to them.
- Melee weapons will not Roll Dodge until they drop to =< 50% health and the target they are focused on attacking is close to them.
- Ranged weapons will Roll Dodge immediately when the target they are focused on attacking comes close to them. They can be surrounded by enemies and not make a move, but once the target they are focused on attacking comes close to them they will take action.
Break Free
Break Free base cooldown is 12 seconds while with 7 Light armor equipped it is reduced to 7.8 seconds.
Blocking
Companions will perform a block when the target they are focused on attacking is performing a Heavy Attack. It does not matter if the target is you, the companion, or anyone else; they will brace for an attack regardless how far away their focused target or who is its intended target. Companions also will not block an attack from an enemy who they are not their focused target they are attacking and will eat the Heavy Attack.
Bashing
Companions will perform a bash/interrupt when the target they are focused on attacking is casting (flashing red) and are in melee range to do so. They will ignore all other enemies around them that are casting if they aren't their focused target they are attacking.
Strafing
"
All Companions will now occasionally dynamically strafe in both melee and ranged combat."
What this means is they will take 3 steps either to the left or right moving in a semi-circle around their target. They will periodically move around, whether or not they are standing in a damage area effect. There is a cooldown, but I haven't figured out what it is or how they decide which direction to move, if at all. They can even move into a damage area effect when they weren't standing in one before if its cast at someone else and they happen to be close to it.
For most players this is a nice addition, for those who know how to control their companions to pin a boss between them and an obstruction may find it annoying when the companion moves around and starts Bashing their target away from the obstruction. Or you want your companion Roll Dodge to go in a certain direction to prevent them from going too far or anywhere at all like against a wall, but now are getting out of place as they strafe left or right from your planned spot.
Player Buffs
This may be the most confusing of all, which Player buffs affect your Companion? This depends on the way abilities and passive apply their buffs, if it's a blanket effect with no target like Molten Weapons or Frost Cloak, it will not affect the Companion. However Class-specific passive effects like Minor Sorcery from the Templar's Illuminate will apply to your Companion. Also any abilities or Ultimate that provides a buff to a target entering or in range of the effect will buff the companion as well. Interestingly enough Aggressive Horn and Light's Champion... does not buff your Companion. I don't know if base game can show it, I use S'rendarr Add-on to see the buffs apply to them and test in combat.
Or if you just want a run-down of what works, what I have found so far:
- Dragon Knight: Mountain's Blessing - Minor Brutality.
- Nightblade: Path of Darkness - Major Expedition, Consuming Darkness - Major Protection, Hemorrhage - Minor Savagery.
- Sorcerer: Exploitation - Minor Prophecy.
- Templar: Illuminate - Minor Sorcery.
- Warden: Any healing spell that can target your Companion - Minor Toughness.
- Necromancer: Nothing.
- Restoration Staff: Combat Prayer - Minor Resolve and Minor Berserk.
There's probably more out there, I haven't found yet.