The Tinkerer

I was thinking more about the way I handle variant classes in my stripped-down class system. All the classes have exactly two class abilities under my approach, and I've been calling one the scaled ability, but I've had trouble naming the other one; I've been calling it "basic ability" or "general ability". Maybe a better name for it would be "universal ability", since all of the non-scaled class abilities are expressed in terms of "All/Always/Any" or "No/Never/None":

• Fighter: use ANY weapon or combat technique
• Magic-User: make or use ANY magic item
• Charmer: use persuasion to reroll reaction in ANY situation
• Cleric: sense or communicate with ANY spirit
• Trickster: use ANY distraction to reroll surprise
• Gifted: sense ANY supernatural force

None of these guarantee or even improve the odds of an outcome, but they give each class an open-ended option that doesn't require training. The scaled ability, in contrast, gives bonuses or tools to influence outcomes.

Within that conceptual framework, I've come up with a variant Trickster: the Tinkerer.

• Tinkerer: solves problems with mechanical ingenuity
  
  • figure out or use ANY machine
  • add HD (or level) bonus when using machines

The universal ability allows Tinkerers to ignore "tech level" restrictions, but does not guarantee success. It just lets a tinkerer have a chance to figure out or use something that other characters can't figure out without training. Their scaled ability is a bonus on the chance to figure out or use. There may be penalties based on the tech level background (something I'm working on as an optional part of Blanc.)

They have a slight overlap with Tricksters in terms of traps. Either can use their bonus as a bonus to a save to avoid a trap and as a bonus to the task of disabling a trap. Either can assemble prepared components into a trap. The Tinkerer, however, can prepare those components without special training, while the Trickster can merely re-assemble parts of a trap. Neither would be able to manufacturer poisons to use in the trap without the appropriate background/training.