Rattlesnakes in GURPS

Crotalus sp.

Rattlesnakes are the iconic venomous snake of North America. While their broad triangular head leading to a prominant neck, thick bodies, and pattern of blotches are distinctive, their most prominant identifying trait is the rattle, or string of dried scales, on the end of their tail. When agitated, they vibrate their tail to produce their infamous buzz, a sound that has sent a chill down the spine of many a hiker. They use this as a warning to avoid being trod upon and to advertize to would-be predators that they are in for a world of hurt if they try to attack.

Rattlesnakes are true pit vipers, capable of sensing and hunting by radiated body heat of their prey. Although usually only painful but not deadly, their bites are occasionally life threatening - or at least can result in the permanent crippling of a limb. Medical care at a well-stocked hospital within an hour of being bitten usually results in a full recovery, although the pain experineced in the meantime may make the victim wish for death until then. A few species pack a potent neurotoxin instead, or in addition to, the usual repertoire of hemotoxins and necrotizing agents. These are considerably more leathal, especially since those with pure neurotoxic venom do not typically cause immediate symptoms leading the victim to delay seeking medical treatment until it is too late.

Rattlesnakes tend to be active in the day during cool weather, and active at night in hot weather. In temperate climates, they over-winter in rocky hibernacula, often in large groups, and disperse in springtime. Survival often requires knowledge of how to find their hibernacua - rattlesnakes transported out of their home range often cannot survive the subsequent winter. All rattlesnakes give live birth.

Some of the more well-known species of rattlesnake are listed below. The default rattelsnake from the main table is a western or prairie rattlesnake.

Species Typical venom Size Range Habitat Notes
Potency Type Typical Maximum
Eastern diamondback, C. adamanteus mild hemo 6
necro 10
algesic 10 2 kg 15 kg Throughout Florida, North up the Atlantic coast through the Carolinas, east from Florida along the Gulf coast to the Mississippi River. Forests, marshes, woodlands, prairies. The largest of the rattlesnakes, and a contender for the largest viper. Although its venom is not incredibly toxic compared to some other species, it can deliver a lot of it making it very dangerous.
Western diamondback, C. atrox weak hemo 10
necro 10
algesic 10 1.5 kg 7 kg Southwestern United States and northern Mexico, from Texas to California. Desert, scrub, and dry forest. Largest of the western rattlesnakes, its venom is comparatively weak.
Sidewinder, C. cerastes mild hemo 10
necro 10
algesic 10 200 g 500 g South California, Arizona, Sonora, and Baja. Sandy deserts. A sidewinding rattlesnake. Pale in color, with small scale horns over its eyes.
Cascabel, C. durissus potent neuro 10 1 kg 6 kg Throughout South America and Caribbean islands of Morro de la Iguana, Tamarindo and Aruba. Savanna, dry shrubland, thorn forest; preferes sandy soils.
Timber rattlesnake, C. horridus (northern population) strong hemo 10
necro 10
algesic 10 1 kg 6 kg United States east of the Great Plains, excepting Florida and the great Lakes region. Deciduous forest in rugged terrain. Mild disposition belies highly toxic venom and large venom yield. Quick to rattle, reluctant to strike, very dangerous when it does connect.
Timber rattlesnake, C. horridus (southern population) strong neuro 10
Black-tailed rattlesnake, C. molossus mild hemo 10
necro 10
algesic 10 500 g 2 kg Interior American Southwest; Arizona, New Mexico, west Texas, most of Mexico. Rocks and boulders, cliffs, scree; scrub, open pine-oak and pine-fir forest, cactus desert, oak savanna, grasslands, chaparral.
Western rattlesnake, C. oreganus medium hemo 10
necro 10
algesic 10 1 kg 4 kg United states from the Pacific Ocean to the Rocky Mountains, southwestern Canada. Rocky outcrops, hillsides, and canyons; scrub, grassland, open conifer woodland.
Southern pacific rattlesnake, C. oreganus helleri extreme hemo 6
necro 6
algesic 6
neuro 10 Southern California and Baja A subspecies of the western rattlesnake with highly neurotoxic venom.
Red diamond rattlesnake, C. ruber weak hemo 10
necro 10
algesic 10 1 kg 4 kg Southern California and Baja. Chaparral, boulders, brush, cactus patches.
Mojave rattlesnake, C. scutulatus potent neuro 10 500 g 2 kg South California and Nevada, inland Mexico. High desert and mountain slopes; mesquite and creosote scrub, cactus and Joshua tree forest, grassy plains. A sidewinding species of rattlesnake. Infamous for its extremely potent neurotoxic venom.
Prairie rattlesnake, C. viridis medium hemo 10
necro 10
algesic 10 1 kg 4 kg American Great Plains and eastern foothills of the Rocky Mountains, from extreme southern Canada to extreme northern Mexico. Grassland, brush. Often shelters in rock ledges or prairie dog tunnels.

Back to Vipers

Species	Typical venom		Size		Range	Habitat	Notes
Species	Potency	Type	Typical	Maximum	Range	Habitat	Notes
Eastern diamondback, C. adamanteus	mild	hemo 6 necro 10 algesic 10	2 kg	15 kg	Throughout Florida, North up the Atlantic coast through the Carolinas, east from Florida along the Gulf coast to the Mississippi River.	Forests, marshes, woodlands, prairies.	The largest of the rattlesnakes, and a contender for the largest viper. Although its venom is not incredibly toxic compared to some other species, it can deliver a lot of it making it very dangerous.
Western diamondback, C. atrox	weak	hemo 10 necro 10 algesic 10	1.5 kg	7 kg	Southwestern United States and northern Mexico, from Texas to California.	Desert, scrub, and dry forest.	Largest of the western rattlesnakes, its venom is comparatively weak.
Sidewinder, C. cerastes	mild	hemo 10 necro 10 algesic 10	200 g	500 g	South California, Arizona, Sonora, and Baja.	Sandy deserts.	A sidewinding rattlesnake. Pale in color, with small scale horns over its eyes.
Cascabel, C. durissus	potent	neuro 10	1 kg	6 kg	Throughout South America and Caribbean islands of Morro de la Iguana, Tamarindo and Aruba.	Savanna, dry shrubland, thorn forest; preferes sandy soils.
Timber rattlesnake, C. horridus (northern population)	strong	hemo 10 necro 10 algesic 10	1 kg	6 kg	United States east of the Great Plains, excepting Florida and the great Lakes region.	Deciduous forest in rugged terrain.	Mild disposition belies highly toxic venom and large venom yield. Quick to rattle, reluctant to strike, very dangerous when it does connect.
Timber rattlesnake, C. horridus (southern population)	strong	neuro 10	1 kg	6 kg		Deciduous forest in rugged terrain.
Black-tailed rattlesnake, C. molossus	mild	hemo 10 necro 10 algesic 10	500 g	2 kg	Interior American Southwest; Arizona, New Mexico, west Texas, most of Mexico.	Rocks and boulders, cliffs, scree; scrub, open pine-oak and pine-fir forest, cactus desert, oak savanna, grasslands, chaparral.
Western rattlesnake, C. oreganus	medium	hemo 10 necro 10 algesic 10	1 kg	4 kg	United states from the Pacific Ocean to the Rocky Mountains, southwestern Canada.	Rocky outcrops, hillsides, and canyons; scrub, grassland, open conifer woodland.
Southern pacific rattlesnake, C. oreganus helleri	extreme	hemo 6 necro 6 algesic 6 neuro 10	1 kg	4 kg	Southern California and Baja		A subspecies of the western rattlesnake with highly neurotoxic venom.
Red diamond rattlesnake, C. ruber	weak	hemo 10 necro 10 algesic 10	1 kg	4 kg	Southern California and Baja.	Chaparral, boulders, brush, cactus patches.
Mojave rattlesnake, C. scutulatus	potent	neuro 10	500 g	2 kg	South California and Nevada, inland Mexico.	High desert and mountain slopes; mesquite and creosote scrub, cactus and Joshua tree forest, grassy plains.	A sidewinding species of rattlesnake. Infamous for its extremely potent neurotoxic venom.
Prairie rattlesnake, C. viridis	medium	hemo 10 necro 10 algesic 10	1 kg	4 kg	American Great Plains and eastern foothills of the Rocky Mountains, from extreme southern Canada to extreme northern Mexico.	Grassland, brush. Often shelters in rock ledges or prairie dog tunnels.