D&D 5E What interesting niche do Gnomes have in your Homebrew Campaigns?

[Ayeffkay]

Villains.

My campaign world suffered some horrible but nonspecific calamity in the past, with a few smallish countries spared immediate destruction, but the vast majority of the overland is an ash covered wasteland where nothing lives.

The gnomes, in the face of this tragedy, flew their airships out to all the little countries they could find, and set up water filtration dams, so that the rivers coming in filled with ash can be used for drinking and crops. Of course, they didn't do this for free - those little countries get to scratch out a life, and the gnomes take some of their harvest so they don't have to grow food themselves. Work smart, not hard.

The gnomes are somewhat dependent on the rest of the people to provide them food, but the people are very dependent on the gnomes to maintain the dams. If one country doesn't want to pay, that's fine, the gnomes have 20 others who will, and that one will come to their senses after a year or so. The gnome homeland (Gnomeland) has so much more than they need anyway, which explains why they're all so tubby.

In one country (where my current campaign began), the gnomes weren't needed due to an ancient portal to the plane of water in their central lake. So, the gnomes sent a strike force to discover why this country refused their help, and sabotage it. For their own safety, of course. The campaign began 6 months after the gnomes arrived, when people were starting to worry about the lake receding...

 

[Bupp]

Rock gnomes on Eska are straight up Star Wars Jawas. Drive around in giant crawlers. They are also the creators of the warforged.

Forest gnomes are your basic pointy hat wearing type.

 

[(Psi)SeveredHead]

I generally steal the culture of Zilargo gnomes from Eberron. The author really put work into making them cool, and explaining their disparate powers such as why they can talk to burrowing creatures. Any "tech" they use is explicitly magitech, so no exploding steam engines.

The Trust is basically the KGB of Zilargo. Do not mess with Zilargo, as the Trust will mess with you. If you are in any way hostile you can't even talk to your friends in private because at least one of those friends has already been killed and replaced using illusory magic. Staff at the hotel (such as cooks trained in the use of alchemical poisons) work for the Trust, directly or just "informing". The street-dwelling gnome lying in front of the hotel is actually a Trust fighter who watches visitors. Actually that is three gnome fighters; they work in shifts but they use illusory magic to look the same, so you don't notice. Wiser visitors will avoid hotels and try to room with some friendly gnomes, but any gnome willing to host a visitor is probably a Trust agent, and the one who has a reputation for being an anti-Trust rebel is actually the daughter of the local Trust leader. Maybe she'll convince you to work with her to take out said leader and take over. Then she will reward you as a traitor deserves.

The mail you encrypted and sent through by courier through Zilargo territory was decrypted and may have been replaced with a completely different message, with the recipient none the wiser since the forgery was really precise, using genuine materials stolen from your country. The visitor who was arrested on trumped up charges and put into Zilargo prison five years ago has either died (all the letters he sent to his family, in his correct handwriting, were forged, and visitors can see a very realistic illusion of him) or worse he was brainwashed and is actively working against his former employers (but of course they don't know that).

Trust no one, not even your friends, since they could be Trust agents wearing your friends' faces. You might not even be able to trust your own thoughts, since they're not afraid of implanting ideas via suggestion spells, picking ones likely to work based on what they read from your mind while you were sleeping.

 

[CleverNickName]

In my campaign:
Gnomes are to halflings, as elves are to humans: they are the longer-lived, capricious, feywild-influenced version of the more common baseline.