"The first warp-spasm seized Cúchulainn, and made him into a monstrous thing, hideous and shapeless, unheard of. His shanks and his joints, every knuckle and angle and organ from head to foot, shook like a tree in the flood or a reed in the stream. His body made a furious twist inside his skin, so that his feet and shins switched to the rear and his heels and calves switched to the front… On his head the temple-sinews stretched to the nape of his neck, each mighty, immense, measureless knob as big as the head of a month-old child… he sucked one eye so deep into his head that a wild crane couldn't probe it onto his cheek out of the depths of his skull; the other eye fell out along his cheek. His mouth weirdly distorted: his cheek peeled back from his jaws until the gullet appeared, his lungs and his liver flapped in his mouth and throat, his lower jaw struck the upper a lion-killing blow, and fiery flakes large as a ram's fleece reached his mouth from his throat… The hair of his head twisted like the tange of a red thornbush stuck in a gap; if a royal apple tree with all its kingly fruit were shaken above him, scarce an apple would reach the ground but each would be spiked on a bristle of his hair as it stood up on his scalp with rage. ”
— from The Táin Thomas Kinsella (translator)
A warp spasm is a berserk rage in which the berserker undergoes substantial physical transformations - usually twisting around inside their skin and becoming hideous in appearance even whilst growing massively in size and strength. In some cases the twisting can be so severe as to hamper the berserker's fighting ability unless he wears a specially designed harness to hold himself together. The spasm may also render the berserker's skin hot enough to boil water.
This is a particular trope of Celtic Myth and specifically of the legendary hero Cu Chulainn but similar transformative rages occasionally pop up in other mythiea. In particular some of the fairy races1 were said to be able to grow in size when a fight was in the offing, usually become significantly less pretty as they did so. Given that Cu Chulainn was meant to be the son of one of the pagan Irish deities and that they and the Tuatha de Danna tended to blend into each other this may not be a coincidence.
Game and Story Use
- The ability to use the warp spasm may be culturally (or racially2) bound or may be open to anyone with the correct training.
- For class-and-level systems, this may be a high level version of the basic berserk fury for whichever class gets raging as their shtick (typically "barbarian" or something similar.
- Possession by the right kind of spirit (as with the original berserkers and ulfhednar) may be necessary.
- Could be a case of spells as powers.