I am going to be starting a new campaign with some friends pretty soon, and so far we have 2 paladins, a divine soul sorcerer, and a gloomstalker ranger, all with standard builds. I’m going to be creating a character for it soon, but I’m not sure what to build. What classes and/or subclasses would best cover any roles we don’t have filled?

Maybe a Wizard or Artificer to cover Skills and knowledges?

Quote from PicklePotato13 >>

I am going to be starting a new campaign with some friends pretty soon, and so far we have 2 paladins, a divine soul sorcerer, and a gloomstalker ranger, all with standard builds. I’m going to be creating a character for it soon, but I’m not sure what to build. What classes and/or subclasses would best cover any roles we don’t have filled?

 

Really, with that mix you could be just about anything. The party already has good melee/tanking, four potential healers, some arcane and divine spell slinging, characters with high CHA to be the face... a sneaky skill monkey type (rogue/bard/monk) might be the obvious "hole" in the party's abilities, but you could even just make a character with the Criminal background to get Stealth and Thieves Tools proficiency to cover that while being whatever class you wanted

Now, hear me out on this... be the party's THIRD PALADIN. Change your group name to the Smite Squad and lay out some divine Justice. You've got three Paladins, a Sorcerer blessed by the Divine Gods, and your Ranger friend who I'm assuming just got swept up in the whole thing.

Quote from TransmorpherDDS >>

Now, hear me out on this... be the party's THIRD PALADIN. Change your group name to the Smite Squad and lay out some divine Justice. You've got three Paladins, a Sorcerer blessed by the Divine Gods, and your Ranger friend who I'm assuming just got swept up in the whole thing.

Reminds me of the party I was in where I played a druid with the entertainer background, alongside three bards and a dragonborn fighter who we decided must be our roadie

You've got lots of healing/tanking, so I'd go for damage. A blaster like a Warlock, wizard, sorcerer, or a rogue if you wanna go more martial. 

If you want a bunch of melee fighters, I'd go with a barbarian or fighter since their pretty neat classes and you mostly already have healing covered.

If you don't want to be a melee fighter, then I'd go with a skill monkey like bard, rogue, or artificer since your party seems to have a lot covered already. Wizard also would work (not as a skill monkey, just for the party) though you guys already have a sorcerer. 

A monk would honestly probably be my recommendation, with the paladins their, I bet they wouldn't take as much damage as usual which helps fix their lowish HP problem. If you want to play a monk with higher HP you could always boost your con score, or take the tough feat. However, you might have to wait before doing either of those since monks are MAD (multiple attribute dependent) and they need their ASI's for their wisdom and dexterity scores.

Artificer is the choice that best covers the party’s holes.  The main things you are missing are (1) skills and tool proficiencies (e.g. thieves tools) and (2) arcane utility spells, ideally ritually cast. You need someone with Detect Magic, Identify, etc.  

A rogue or bard can do #1 about as well as an Artificer.  But the limited spells known for bards and Arcane Tricksters make #2 hard.  Wizards can easily handle #2, but you’ll need a background like Criminal to get proficiency in Thieves Tools.  Artificer can do it all, although they do need to prepare spells for rituals.

Like your paladins and ranger, you aren’t going to be casting all the time, except maybe cantrips.  Plan on a leveled spell or two in each combat, with most of your casting out of combat.

You might even consider a two level dip in Wizard to get better ritual casting and subclass benefits.  War with Armorer and Evoker with Artillerist are good subclass matches, but pick your favorite.  Wait until at least level 5 though.

I would say wizard. Focus on control, buff, and debuff. Sure have some damage spells ready (single target and AOE) but the rest of the party seems more than adequate for dealing out damage. Why not make it easier for them to do it?

And as was mentioned, pick up ritual spells as you level, along with the rest. As long as they are in your spell book you don’t have to prepare them. 

You might find it helpful to have a good Dex and/or the alert feat to help win the initiative so you don’t catch the party in any AOE spells like faerie Fire or hypnotic pattern

Thanks for all the ideas, it seems like an artificer should work for the intelligence/support/tools role which we don’t have covered yet.

I have to admit... even though I joked about going Paladin, I think you made the right choice with Artificer.

The best option would be support/utility. You have a charisma character so I'd keep away from a bard but a cleric or druid might be nice. A wizard could also be an option.