5e Dwarf Fighter/Barbarian or Barbarian/Fighter.

[Klaus Teufel]

We're starting a new campaign, and I thought we were starting 2nd or 3rd level, so I was going to go Barb1 then Fighter1 and create a trollslayer/doomseeker style Dwarf with 2 wpn fighting dual handaxes.

But now it turns out that we're starting at first level. Multiclassing has always been a bit confusing to me: Do I lose anything essential by taking Fighter at first level to get 2WF, then taking Barbarian going forwards?

[Unoriginal]

We're starting a new campaign, and I thought we were starting 2nd or 3rd level, so I was going to go Barb1 then Fighter1 and create a trollslayer/doomseeker style Dwarf with 2 wpn fighting dual handaxes.

But now it turns out that we're starting at first level. Multiclassing has always been a bit confusing to me: Do I lose anything essential by taking Fighter at first level to get 2WF, then taking Barbarian going forwards?

You lose 2 HPs, and you gain a couple of proficiencies you likely won't use as a Barbarian (mostly heavy armor proficiency, tbf).

That being said, you don't need that Fighting Style to dual-wield handaxes, and you don't need to take a Fighter level to get that Fighting Style in the first place. Do you have any other reason to take a Fighter level?

[stoutstien]

We're starting a new campaign, and I thought we were starting 2nd or 3rd level, so I was going to go Barb1 then Fighter1 and create a trollslayer/doomseeker style Dwarf with 2 wpn fighting dual handaxes.

But now it turns out that we're starting at first level. Multiclassing has always been a bit confusing to me: Do I lose anything essential by taking Fighter at first level to get 2WF, then taking Barbarian going forwards?

If the only thing you want from fighter is the twf style it's probably not worth it. Barbarian is pretty packed 1-5 and you could still pick up the style via a feat at lv 4 without losing that progression.

[CheddarChampion]

Which Barbarian subclass were you thinking of taking?
Are you using Tasha's rules?
If you're attached to the idea of not wearing armor, you probably want more Barbarian levels for the extra HP and the extra uses of Rage.

Here's my suggestion:
Hill Dwarf w/ Tasha's Rules: 16/14/16/8/10/10
Level Progression: Zealot 5/Champion or Battle Master 3/Zealot X, maybe with a 4th level of Fighter if you want an extra Feat/ASI.
Feat/ASI Progression: Str +2, Str +2, and then whatever works best for your campaign: Tough, Sentinel, Mobile, Resilient (Wisdom), Mage Slayer, Dual Wielder.

[Frogreaver]

We're starting a new campaign, and I thought we were starting 2nd or 3rd level, so I was going to go Barb1 then Fighter1 and create a trollslayer/doomseeker style Dwarf with 2 wpn fighting dual handaxes.

But now it turns out that we're starting at first level. Multiclassing has always been a bit confusing to me: Do I lose anything essential by taking Fighter at first level to get 2WF, then taking Barbarian going forwards?

The difference between 1d6+5 + 1d6+2 and 1d6+5 + 1d6+5 is small enough that I wouldn't worry about the style early.

As such I'd start Barbarian and stay Barbarian straight till 5th level. Barbarians are just too loaded early to take a detour IMO. At some point after 5th you should consider the multiclass into fighter but go at least 3 levels (4 for the ASI is fine too). That nets you TWF Style, Action Surge, Subclass abilitiy like Battlemaster Manuevers.

[Ir0ns0ul]

You could forgo Fighter at all by going Berserker Barbarian and customizing the bonus action attack from Frenzy as a much better two-weapon fighting approach.

[Klaus Teufel]

The difference between 1d6+5 + 1d6+2 and 1d6+5 + 1d6+5 is small enough that I wouldn't worry about the style early.

As such I'd start Barbarian and stay Barbarian straight till 5th level. Barbarians are just too loaded early to take a detour IMO. At some point after 5th you should consider the multiclass into fighter but go at least 3 levels (4 for the ASI is fine too). That nets you TWF Style, Action Surge, Subclass abilitiy like Battlemaster Manuevers.

You have a very good point.

[SLOTHRPG95]

You could forgo Fighter at all by going Berserker Barbarian and customizing the bonus action attack from Frenzy as a much better two-weapon fighting approach.

The cost of Frenzy is pretty brutal, though. Some DMs will give you a few free uses before you start paying in Exhaustion, but otherwise it's not really comparable in cost to just picking up two weapons for an off-hand attack.

[Klaus Teufel]

If it helps, my rolls were: 18, 13, 15, 11, 12, 9, so with Mountain Dwarf we get 20, 13, 17, 11, 12, 9.

[Keravath]

If it helps, my rolls were: 18, 13, 15, 11, 12, 9, so with Mountain Dwarf we get 20, 13, 17, 11, 12, 9.

I would stick with straight barbarian to 5 if you want to play barb. Your first ASI is likely to be +1 dex/+1 con for a 2 AC bump, hit points, initiative and improved ranged weapon attacks. I don't think any other choice of ASI would get you as much.

You can add 3-4 levels of fighter later for the archetype, ASI, action surge and second wind (champion improved crits can work pretty well with reckless attack).

Depending on how high a level your campaign might go to ... it can be worth considering whether you want to be a fighter with a few levels of barbarian (in which case start with 5 levels of fighter) or a barbarian with a few levels of fighter. The advantage to the fighter approach is that level 11 fighter picks up an additional attack while barbarian doesn't pick up anything equivalent.

Finally, if you are planning on using TWF then consider what other abilities you might have that will conflict with the use of the bonus action.