DnD 5e - The Gnome Handbook
Last Updated: February 28th, 2020
I will use 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.
Gnomes have changed a lot throughout the history of Dungeons and Dragons. At times they've been monsters. At times they've been fey. In general DnD has always had trouble pinning down gnomes thematically in a way that distinguishes them from halflings, but I think 5th edition may have done the best job of any prior edition. Gnomes have subraces which are very disting from one another, and their traits offer some unique an interesting options.
The Gnome's biggest challenge is their ability score increases. All gnomes share an Intelligence increase which predisposes them to being artificers and wizard, but generally you'll only have one or two viable subraces for any other class. Gnomes are generally a niche option that works well in specific builds, but the Gnome simply doesn't have the right ability score increases to fill a broad range of character options.
Gnomes get the crucial Intelligence increase as a core gnome racial trait, so any subrace works fine. Rock Gnome fits thematically because of the Tinker trait, but you don't need it to succeed.
No Strength increase.
No Charisma increase. A Dexterity increase is available to the Forest Gnome, but that's not enough to make the Bard tempting.
No Wisdom increase.
No Wisdom increase. Forest gnomes seem like they would make a natural Druid, but the ability scores don't work and Speak With Small Beasts is more amusing than useful.
The Fighter is your best bet for a front-line melee gnome. Deep Gnome and Forest Gnome both get Dexterity increases, and between a Dextery increase and Intelligence increase the Eldritch Knight is an obvious choice.
Forest gnomes get the crucial Dexterity increase that you need to make the Monk work, but you don't get much else.
You can argue that Dexterity is enough to make a paladin work, but on its own that's not going to be especially effective.
The Deep Gnome and the Forest Gnome both provide Dexterity increases, which is crucial for the Ranger. Unfortunately, the Ranger benefits very little from the Gnome's other traits.
The Deep Gnome and the Forest Gnome both make great rogues of any kind, but Arcane Trickster is a natural fit thanks to the Intelligence increase and the Forest Gnome gives you Minor Illusion so you can get a taste of magic before you hit level 3.
Mark of Scribing offers a Charisma increase, plus some additional spellcasting options. Wizard is typically a better option due the Gnome's base Intelligence increase, but a +1 Charisma increase is technically the only thing that the Sorcerer absolutely needs.
Mark of Scribing offers a Charisma increase, plus some additional spellcasting options. Wizard is typically a better option due the Gnome's base Intelligence increase, but a +1 Charisma increase is technically the only thing that the Warlock absolutely needs.
An intelligence increase as a core racial trait means that any gnome subrace can make an excellent wizard.
A great defensive option, especially for frail classes like the Wizard. If you use this early in an enemy's turn, they might be forced to make attacks against you while you're invisible, potentially causing them to miss. You can then spend your turn to get somewhere safe.
Only useful if you're extremely worried about being grappled.
Dragonmarks are detailed in Eberron: Rising from the Last War. Gnomes treat dragonmarks like a subrace, adding its traits to the core gnome traits.
Mark of Scribing
A Charisma increase and an Intelligence increase are unusual to find on the same race (Tieflings are notably the only other race with the same increases), and granting a Charisma increase doesn't do anything to broaden the Gnome's appeal beyond classes that depend on casting spells. Sorcerer and Warlock become viable options for the Gnome, but the Paladin is a bad option without a Strength or Dexterity increase.