Does weapon damage effect pet damage?

If not, then what exactly does all?

Your player character’s weapon damage doesn’t effect pet damage whether it’s pet-scaled or player-scaled.

Player-scaled pets act like pure damage spells like Grenado or Trozan’s Sky Shard (without the Iskandra set). The only way to increase their damage is via more skill ranks or modifiers to increase their base damage, conversion to merge the majority into one damage type, % damage or in unique cases increasing their attack speed (Guardian of Empyrion for example has modifiers that do this).

Pet-scaled pets have their own default attack that deals an amount of base damage that can be augmented further by providing them with more damage through buffs or equipment that feature it beneath the “Bonus to all Pets” banner like Corruptor’s Mask or via auras like Blood of Dreeg that act as buffs that apply to nearby allies (NPCs, other players and as mentioned your pets or your allies pets). Like the above skill ranks, conversion and more attack/cast speed are ways of increasing their damage output. Their total pet damage is then increased by a % damage stat specific to pets.

Thanks for the detailed reply friend, much appreciated. Thus if I understand it correctly, one can as in Diablo 2 when buying a +3 Raise Skeleton with +3 Skeleton Mastery wand bought in early game have an end game worthy weapon if one get for instance a +25% to pet damage sword early in Grim Dawn as well?

Asking because I play a Cabalist and picked up a weapon early on with high %damage to all pet damage, best to keep this weapon then?

The skill ranks to Raise Skeletons are valuable yes. The % damage is nice and while getting more matters early on, it’ll become less impactful over time/at higher levels when you pick up more of it from gear and procs and other stats like pet OA/crit damage/total speed come into the forefront.

I see, thanks friend.