Addiction comes in two forms: mental (affecting the ego) and physical (affecting the biomorph). The character or morph is addicted to a drug (p. 317, EP), stimulus (XP), or activity (mesh use) to a degree that impacts the character's physical or mental health. Players and gamemasters should work together to agree on addictions that are appropriate for their game. A minor addiction is largely kept under control-it does not ruin the character's life, though it may create some difficulties. The character may not even recognize or admit they have a problem. The character must indulge the addiction at least once a week, though they can go for longer without too much difficulty. If they fail to get their weekly dose, they suffer a −10 modifier on all actions until they get their fix.