Another of my “micro-rules” this time expanding on the idea of Complementary Rolls (GURPS Action 2: Exploits, p. 5; GURPS: Social Engineering, p. 21, 31, 48), but using attributes instead.
How It Works
Attribute synergy uses the same rules as complementary skills rolls – make a roll and give a +1 to another roll if you succeed, -1 if you fail, -2 if you critical fail, or +2 if you critically succeed. Any roll can benefit from attribute synergy from another attribute except when rolling that attribute itself. For example, you could use DX to enhance a damage roll, but not ST since damage is based on ST. Most of the time this should be obvious to both the GM and player, but if not using the following.
- ST cannot be used for damage rolls, anything involving lifting, or “brute force” skills (e.g., Forced Entry), weapon skills (e.g., Axe/Mace), or unarmed combat skills (e.g., Brawling).
- DX cannot be used for rolls to keep your balance, movement, active defenses, etc. It also cannot be used for any DX-based skill or skills related to nimbleness or agility (e.g., Surgery or Mechanic to do fine work).
- IQ cannot be used reaction rolls or any IQ-based skill.
- HT cannot be used for rolls related to physical toughness (e.g., death checks or rolls for mortal wounds) or HT-based skills.
- Will cannot be used for any Will-based skill or rolls related to mental toughness or concentration.
- Per cannot be used for any Per-based skill or rolls related to perspicacity or awareness.
Unlike Complementary Rolls, Attribute Synergy rolls do take any relevant penalties (e.g., Vision penalties when rolling Perception) thus making them a riskier proposition.
Example 1: Ani wants to use her high Perception roll to enhance her damage roll since her ST is not so high. The GM agrees that this should be possible, but gives her a -2 to her roll because of the Vision penalty for not having sufficient light. Succeeding her Perception roll she adds +1 to her damage roll. If she had failed she’d take -1 instead.
Example 2: Shaw wants to use his sheer force of Will to socially coerce the bartender using his Fast-Talk skill. Failing his roll he instead rollings Fast-Talk at a -1 – if he had critically failed he’d take a -2 instead.
Picking Over the Bones
I have no idea if this would actually work in game play. The idea is fairly solid – but it could impact game sessions causing them to slow down as every player ekes out the best possible bonus. One thing that came to mind writing this was the idea that you could take a penalty to your roll to increase the bonus your complementary or attribute synergy roll gives. I’d think each -2 or -4 to your roll would give you a +1 should you succeed, but that might be too low. My gut says at least a -5 per +1 as that’s likely less easy to abuse.