Equipment Modifiers

The quality of your equipment modifies your skill rolls for tasks that normally require equipment:

• No equipment: -10 for technological skills, -5 for other skills. Note that many skills cannot be used at all without equipment!
• Improvised equipment: -5 for technological skills, -2 for other skills.
• Basic equipment: No modifier. This is the case most of the time.
• Good-quality equipment: +1. Costs about 5× basic price.
• Fine-quality equipment: +2. Costs about 20× basic price.
• Best equipment possible at your TL: +TL/2, round down (minimum +2). Not usually for sale!

If you have “basic” or better equipment that is not in perfect condition, the following modifiers apply in addition to quality modifiers:

• Missing important items: -1 per item.
• Damaged equipment: -1 to -3.

Equipment modifiers reflect the quality of:

• Special “tools of the trade,” for criminal, military, and espionage skills such as Disguise, Explosives, Forgery, Forward Observer, Holdout, and Lockpicking.
• The contents of your backpack, for outdoor skills like Fishing and Survival.
• Your instruments or lab, for scientific and medical skills such as Alchemy, Diagnosis, Hobbies/RPGs/Carrouban GURPS/Rules/Skills/Meteorology, Navigation, and Surgery.
• Your shop or toolkit, for Armoury, Carpentry, Electrician, Electronics Repair, Engineer, Machinist, Masonry, Mechanic, Smith, and other skills used to build or repair things.
• Your studio, for artistic skills – Artist, Jeweler, Photography, etc.

Example: For First Aid skill, “improvised” might mean leaves and clean mud; “basic,” sterile bandages; “good,” a standard first-aid kit; “fine,” a crash kit (found in most ambulances); and “best,” an entire hospital. Missing antiseptic would give -1, while a first-aid kit salvaged from a wrecked vehicle might give -1 or worse for damaged equipment.

Source: GURPS 4th - Basic Set - Combined, page 345 (PDF page 349)