GURPS SKill Modifiers

There are a lot of modifiers that can be applied to skill rolls.  This article tries to list the location of most of them. Remember to check skill entries as well for they often have specific modifiers.  Once you have used them a few times it is pretty easy to eyeball them during a game and come rather close if you don't want to take the time to look them up.

General skill modifiers

Modifiers can make simple tasks taking plenty of time very easy, or extremely difficult - depends on the circumstances and what your trying to do. Some handy references...
  • Climbing (p. B349)
  • Culture (p. B23) Social skills.
  • Different Gravity (p. B350)
  • Equipment Modifiers (p. B345)
  • Familiarity Penalties (p. B169)
  • Geographical and Temporal Scope (p. B176)
  • Influence Rolls (p. B359)
  • Language (p. B23)
  • Long Tasks (p. B346)
  • Physiology Modifiers (p. B181) All medical skills
  • Planet Types (p. B180) For Biology, Geography (Physical), Geology, Meteorology.
  • Sense Rolls (p. B358)
  • Success Rolls (p. B347)
  • Swimming (p. B354)
  • Tech-Level Modifiers (p. B168)
  • Task Difficulty Modifiers (p. B345)
  • Time Spent (p. B346)
  • Will Rolls and Fright Checks (p. B360-361)
Bill Stoddard wrote an article called Everyman Tasks in Pyramid #3/65 Alternate GURPS III that lists even more common modifiers for skills. You can refer to it for lots of further examples.

Skill Contests

  • Quick Contests (p. B348) Rules for a fast competition between opposing people.
  • Regular Contests (p. B349) More involved competition.


  1. I feel like this could have a list of Advantages that enhance skills and what they enhance. Right now it feels a little barebones and not very helpful when you're looking for the tchy little bonuses lying around.

    1. I thought about that but think that is too much info to put up here. Its in various books and I am concerned about putting more than a page reference so as to not violate copyright.