Mechanic

#skill
TL; must specialise; IQ/Average; Defaults: IQ-5, Engineer (same)-4, or Machinist-5.

This is the ability to diagnose and fix ordinary mechanical problems. A successful skill roll will let you find or repair one problem.

You must pick a specialty from within one of these four categories:

Mechanic specialties default to one another at -4, although the GM may modify this for particularly close or distant specialties. The systems covered by each specialty vary by TL. For instance, Mechanic (Light Airplane) covers single-engine biplanes at early TL6, small private jets at TL7, and so forth.

Familiarity is very important here. For instance, Mechanic/TL7 (Light Airplane) covers both propeller-powered seaplanes and small private jets, but going from one to the other gives you -2 for an unfamiliar item (prop-powered plane to jet) and -2 for an unfamiliar implementation (seaplane to regular plane), for a net -4 to skill until you familiarize yourself with all the differences.

Modifiers: -2 for an unfamiliar item within your specialty (e.g., a barge when you’re used to battleships), or for an unfamiliar implementation (e.g., a powerboat engine when you’re used to automobile engines); equipment modifiers (p. 345).

Source: B207