Im playing a Fighter Echo Knight level 6 at the moment. Ive been using the Longsword and i just realised that my damage potential is 9 - 16 since i got a homebrew magic longsword that makes my longsword damage a 1d8 + 8 at level 6, so im not sure if when i gain levels, should i swap to a greatsword build when i gain more levels, or should i just continue playing longsword and eventually ill get either a homebrew one from GM that makes me deal more damage per swing, or a feat/something in the book that allows me to deal 20 or more damage per swing?

at the moment, it feels like my damage per hit is lacking, and the only saving grace is that i do like thrice to six times the 1d8 + 8 damage per turn.

3d8+24 worth if just weapon attacks is quite nice I'd say.

I mean longswords are bad as a weapon but if it's the only magic weapon available dealing extra dmg its prolly still worth.

But Dueling + quarterstaff + PAM is the best you can do with a 1 handed weapon

Dueling basically just brings your damage with a 1-handed weapon roughly up to par with a 2-handed weapon (eg, 1d8+2 = 6.5, while 2d6 = 7), while letting you use a shield.

So Dueling + longsword works out to be sacrifice only a tiny amount of damage for +1 AC compared to a Great Sword + Defense fighting style.

If you're level 6 at the moment, I'm assuming you have a 4 or 5 for your Strength modifier, so I'm assuming then that your magic weapon is either a regular (but very strong for this tier of play) +3 Longsword, or a custom magic item that only buffs your damage and not your hit chance? Maybe with +3 or +4 to damage? Regardless, that won't impact the fighting style calc all that much, if you think you'll get a comparable Great Sword at some point.

I mean, if we're talking feats then PAM + GWM + 2-handed polearm, offsetting the lack of shield with Defense, would be a much more optimal way to go.

I don't really think it's worth considering for this topic though, consider OP has an existing character that probably already has their feats/ASI locked in.

If you do 2H you can get the feat for extra damage (Heavy weapon master) and I don’t think there’s anything similar you can get for the long sword

Are you playing 5.0e or 5.5e? More specifically, what version of the Great Weapon Master feat is in the game?

What exactly does the sword do? Does it specifically increase damage only, or is it like a more normal +x sword that gives a bonus to accuracy and damage?

Dueling allows a martial character to gain the massive defensive benefits of a shield without sacrificing much of their basic DPR. Usually that trick is reserved for characters that really shouldn't be using them at all, i.e. arcane full casters.

It's a good pick if the extra defense fits with the character's role in combat.

They could go that way but the AC from a shield with a quarterstaff is competitive enough to deal usable damage

It’s actually both!

One-handed weapons in general just aren’t worth giving up the damage you would be dealing with a two-handed weapon, especially since you (usually) need a two-handed weapon to be able to use either of the power attack feats, which is the source of a large chunk of martial damage output.

Additionally, Dueling is one of the worst fighting styles, just mathematically.

the magic item only buffs a +1 on rolls and damage

but i have +5 strength, so the magic weapon i have rn does 1d8 + 5 + 2 (from dueling) + 2 (from the magic item bonus)

my feats atm are heavy armor master and shield master, i think when i level up and when i choose to switch to another weapon i can replace the shield master feat with GWM and PAM when i get another feat slot

the sword i have rn increases chances to hit and damage by +1, and additionally gives second wind +1d10 temp hp on top of the already existing +1d10 perm hp

I'd recommend two handing with an eccho knight. Wielding a shield doesn't change your echos ac and if you play right you can always be attacking through it at range. If you use a maul and the pusher feat you can always keep distance between yourself and your enemies

damn my gm overglazed the dueling fighting style i see