Warhammer 40,000: Rogue Trader (1987), p247 — Sub-Plots

One of the players' models has unknowingly contracted a dose of MACS (Mysteriously Acquired Crazy Syndrome). The disease takes hold instantly and without warning, causing the victim to act in a totally uncontrolled, murderous and unpredictably dangerous manner until mercifully slain. MACS may be mysteriously transmitted through any sort of protective clothing, wall, armour plating etc. Any creature of the same race has a 1 in 6 chance of contracting the disease if it comes within 2" of the victim. This manifests itself at the beginning of any following turn on the D6 roll of a 6.