Affliction is a physical, exotic advantage described in Basic Set, p. 35-36, and referenced in GURPS Powers™, pp. 9, 17, 21, 31, 39-41, 118, and 169. Affliction is subject to a wide range of enhancements and limitations and is often used to build superpowers or other unnatural effects, and is the base advantage used to build 'buff' style powers that benefit your allies.
mentions inverting the HT roll. Penalty becomes bonus, and the HT roll must succeed to get the power instead of failing to get the power. Happens with the willing.
http://www.sjgames.com/gurps/faq/FAQ4-3.html#SS3.2.12 mentions potential Size Modifier restrictions
- On HT rolls for beneficial Afflictions , , 
- On Afflictions causing multiple effects 
- On getting Affliction past armor 
- On affecting inanimate objects 
- On combat techniques not causing Afflictions unless so noted 
- On Affliction affecting defenses and reaction rolls if it causes an attribute penalty 
- On SM penalties and cutoffs 
- On the Choking Affliction versus the Choke spell 
- On designing spells with Affliction-like effects 
- On his ambivalence about the cost structure 
- To be honest, it bugs me some, too.* Were I doing it over again, I'd probably set up Affliction more like Leech or Terror and say that it's x points to be able to do it at all and then y points/level to do it more effectively, where x > y. Modifiers would apply to the final cost. It's hard to say what fair values of x and y would be in this model (Leech uses x = 25, y = 4, while Terror uses x = 30, y = 10), but I'd start at x = 10, y = 2 and see how balanced it was.
- On two possible ways to change the cost 
- Part of me likes 10 + 3/level and simply taking the penalty off recovery rolls.
- Part of me thinks that maybe we should just define a per-die cost, as with Innate Attack, and require the Affliction roll to exceed DR and cause a HT roll at -1 per 2 points penetrating, as with Side Effect. That way, Affliction 1d would work against unarmored normals, Affliction 10d would be enough to zap most humans with HT 1-20, and you could go nuts with Affliction 10d(10) or 100d or whatever to stun guys in battlesuits. And of course the countless places where the rules get all complicated and have to approximate Affliction levels with damage dice would go away. And Absorption could work vs. Affliction.
Racial Templates Edit
Affliction appears on the follow racial templates
- Djinn Ascended Ones in Banestorm p. 189
- Medusas in Banestorm p. 195
- Lilith in Fantasy p. 54
- Imp in Fantasy p. 109
- Larva in Fantasy p. 213
- Skunk lens of Wolverine in Dungeon Fantasy 5 - Allies p. 11
- Shoulder Dragon in Dungeon Fantasy 5 - Allies p. 28
Affliction appears in the following bestiary entries
- Giant Spiders in Banestorm p. 221
- Wyverns in Banestorm p. 226
- Miser Troll in Creatures of the Night Vol. 2 p. 5
- Urimander in Creatures of the Night Vol. 2 p. 17
- Chronochaotic Spider in Creatures of the Night Vol. 3 p. 4
- Flutter Devil in Creatures of the Night Vol. 4 p. 9
- Trantid in Creatures of the Night Vol. 4 p. 11
- Watchtower Spirit in Creatures of the Night Vol. 19
- Herecine in Fantasy p. 47
- Panther in Fantasy p. 49
- Hellkittens in Banestorm - Abydos p. 58