DnD 5e - The Firbolg Handbook
Last Updated: February 21st, 2020
RPGBOT uses the color coding scheme which has become common among Pathfinder build handbooks, which is simple to understand and easy to read at a glance.
- : Bad, useless options, or options which are extremely situational.
- : OK options, or useful options that only apply in rare circumstances.
- : Good options.
- : Fantastic options, often essential to the function of your character.
I will not include 3rd-party content, including content from DMs Guild, even if it is my own, because I can't assume that your game will allow 3rd-party content or homebrew. I also won't cover Unearthed Arcana content because it's not finalized, and I can't guarantee that it will be available to you in your games.
The advice offered below is based on the current State of the Character Optimization Meta as of when the article was last updated. Keep in mind that the state of the meta periodically changes as new source materials are released and this article will be updating accordingly as time allows.
The Firbolg is an interesting race, combining an uncommon pair of ability score increases with powerful innate spellcasting. Their flavor text describes them as natural druids, and while that can be a great option it's also not the only one. Tragically, as much fun as the Firbolg is conceptually their unusual combination of ability increase severely limits their build options.
Speech of Beast and Leaf
The Firbolg's Speech of Beast and Leaf feature is worded very simply, but the exact applications might be confusing. Speech of Beast and Leaf does not replicate the effects of the Speak With Animals and Speak With Plants spells, and it works differently from the Gnome's Speak With Small Beasts feature. Speech of Beast and Leaf is more akin to Kronk talking to squirrels, but you can't understand the animal or plant in return.
The text of the ability also doesn't specifically state that Speech of Beast and Leaf only applies to creatures, so it's not explicitly stated how it applies to inanimate plants like a mundane tree or something. But with some critical thinking we can work it out.
Speaking to beasts is the easy part. "Beasts" is a creature type which includes things like animals and giant bugs, ranging from the smallest rat to the largest dinosaur. Since creatures like mundane bugs (house flies, normal spiders, etc.) aren't given stat blocks it's not totally clear if you can talk to them, but as a DM I would allow it.
Speaking to plants is more complicated. Without magic, most mundane plants are inanimate and don't have senses like humanoids do. Your DM might allow mundane plants to respond to extremely simple commands, like asking a venus fly trap to open or shut, but anything beyond the plant's normal capabilities would require magic no matter how charming you were.
Plant creatures are another story, having more in common with beasts than with mundane plants. You might encounter a shambling mound and convince it not to eat you rather than getting into a fight with what amounts to a compost elemental. Most plant creatures don't speak a language, so this is a wholly unique option for handling them.
To make best use of Speech of Beast and Leaf, you'll need to invest in Face skills like Persuasion. Without a natural Charisma increase, that's an unusual role for the Firbolg. But spending one skill proficiency on Persuasion may be enough to mostly negate plant creatures as threats to your party, which might be worth the investment in some games.
Classes (Default Rules)
This section assumes that you're not using the option "Customizing Your Origin" rules presented in Tasha's Cauldron of Everything. If you are using those rules, scroll up to the previous section.
No Intelligence increase.
A Strength increase is just barely enough, but nothing else about the Firbolg supports the Barbarian.
The Bard needs a Dexterity increase, a Charisma increase, or both. The Firbolg gets neither.
Despite their flavor text, the Firbolg makes a better cleric than a druid. Druids can rely on Wisdom for melee attacks thanks to Shillelagh, but Clerics are stuck using Strength or Dexterity. A Strength increase makes that much easier, allowing for a wide range of melee cleric builds. If you still want a druidic feel, Nature is a great option.
Wisdom is the only thing that the Druid strictly needs, so the Firbolg is a natural choice both mechanically and thematically. A Strength increase might tempt you into melee, but if you're going that route Shillelagh and Wild Shape are better options than trying to rely on Strength.
A Strength increase is just barely enough, but nothing else about the Firbolg supports the Fighter.
Wisdom is great, but the Monk's primary role is as a Striker so they can't afford to lag defensively by not getting a Dexterity increase.
A Strength increase is just barely enough, but nothing else about the Firbolg supports the Paladin.
Dexterity is typically the Ranger's primary ability score, but in medium armor the Ranger can work with Strength. The Firbolg's innate spellcasting offers some useful magical and stealth options which the Ranger normally can't provide, offering new stealth options to help compensate for your relatively poor Dexterity.
The Firbolg's innate spellcasting is neat for a rogue, but it's simply not enough to make the Rogue a good option since you don't get a Dexterity increase.
No Charisma increase.
No Charisma increase.
No Intelligence increase.