Some of my personal “Gnome” headcanon that I employ regularly in roleplay:
• The fall of Gnomeregan was so devastating in terms of population because a series of failed evacuations preceded the Gnomes turning to that infamous irradiated solution.
• Gnomeregan suffered a series of power failures, which rendered escape to the surface difficult as doors and consoles didn’t work.
• Some Gnomes actually suffer from a form of PTSD that particularly focuses on underground environments and claustrophobic spaces due to Gnomeregan.
• Gnomes are acutely aware that most of their “best” designs are made in concert with Dwarves, who simplify their overengineered ideas into something workable on a massed scale.
• Meritocratic society can be very exclusionary. Gnomes who aren’t great engineers are viewed poorly and ostracized socially. It can also impact their career chances.
• The Gnomish equivalent of a Marshall in terms of military rank is a Mekgineer. This has been largely retired as a rank because of Themaplugg.
• Officers in the Gnomish military are typically poor leaders, this is because they gain positions thanks to their engineering ability, not their tactical prowess or leadership qualities.
• Gnomish dissidents exist. Not everyone agrees with Mekkatorque; some Gnomes believe it’s been too long since the Tinker’s Court voted on a new leader.
• The lack of a Gnomish historiography is due largely to a preoccupation with “progress”. Some believe that the Bronzebeard fascination with the Titans is archaic.
• Gnomes share a great affinity with the Bronzebeard Dwarves but they do not see Dark Irons or Wildhammer Dwarves in the same light. The presence of Dark Iron Dwarves in Gnomeregan causes a great level of distrust.
• Gnomes are reliant on Humans and Dwarves for their agrarian needs, given that they don’t put a great emphasis on farming.
• The Gnomish tendency towards overt optimism is a reflex given the relative hopelessness they sometimes find themselves in.
• Gnomish fertility rates are incredibly low due to the irradiation of Gnomeregan. This is why the race has struggled to regain pre-WoW population levels.
• Leprosy in Gnomes can cause psychological issues and brain damage, even when surface symptoms aren’t obvious.
I probably got more tbh, but I can’t think of it atm.