Vipers in GURPS

The vipers

Vipers are a group of highly venomous snakes. They are typically heavy-set and slow moving animals, but capable of blazing fast strikes. Their heads are characteristically arrow-head shaped, with the broad jaws significantly wider than the neck. Vipers typically rest in a tight coil, and this pose is how they are commonly encountered.

Vipers are cold blooded. They need heat to digest their food and sustain vigorous activity, but they cannot generate that heat themselves so they must get it by basking in the sun or resting in warm places (such as on sun-warmed rocks). If they get too hot they will cool off by retreating out of the sun and into someplace cooler. Vipers typically take shelter under rocks, fallen logs, or in crevices or burrows. These refuges also provide protection from predators and a humid environment to limit water loss through respiration. A viper in the open feels exposed and vulnerable - it can only really rest when it has the tight confines of its shelter squeezing in on it from all sides.

Like most reptiles, vipers main sense of the world is smell. They use it to find prey and mates, communicate, warn them of danger, and identify things. As with all snakes, they smell by flicking their tongue out to pick up scent particles and transfer them to a chemosensory organ on the roof of their mouth. Viper's eyesight is not spectacular - they can sense motion well enough but lack the brainpower to process details or recognize objects. One family of vipers - the pit vipers - use specialized pits in their face to detect radiated heat. This gives them some level of infravision. The resolution is poor, but it is good enough to allow them to target prey with their strikes using heat alone. Vipers are nearly deaf to airborn sounds, but they can pick up vibrations through the ground and use this to warn them of approaching danger.

Vipers are typically ambush predators. They sit coiled in one spot waiting for prey to wander by. With their cryptic patterns, they are hard to spot and they can often take their victims by surprise. The viper will lash out in a rapid strike; its long fangs, normally stored folded against the gums, will swing out to jab deep into the hapless target. In an instant, powerful muscles around the venom glands contract, injecting a dose of toxins. The viper then releases and withdraws. The prey animal then typically runs off, saving the viper from potential injury. A viper can smell its own venom, as the poison takes effect the viper begins to leisurly track its upcoming meal. When it comes upon its incapacitated quarry, it will begin to eat it whole and headfirst. Snakes are unable to dismember or tear apart their meals, but can distend their jaws to a remarkable extent to swallow food of much larger girth than the snake itself.

The excellent camouflage and cryptic habits of vipers also means that people walking by may not see the viper in their path and accidentally tread on it. Directly stepping on a viper usually means getting bit with a full dose of venom. Fortunately, vipers would rather not get stepped on, and would rather not waste their venom on something they can't eat (and leaving them vulnerable until their venom supply replenishes). When they detect something big and potentially dangerous coming toward them they usually get out of the way. If they are surprised at close range, they may put on a threat display to warn off the intruder. This may involve hissing or puffing up or any number of other species-specific warning signs, but it usually involves a coiled body with the front 1/2 to 1/3 of the body held in an S-shape, ready to strike.

Most vipers give live birth.

Vipers will be found where there is shelter, warmth, food, and (depending on the species) water. The food the viper is following, in turn, is attracted to its own food, plus water and shelter. Rock piles, wood piles, fallen logs, or old junk such as metal sheets or wooden planks provide shelter for both the viper and its prey. Farmland is often particularly attractive, because the grains bring rodents to feed on, and farmers invariably leave things to hide under lying around. Bare, open areas are likely to be free of vipers.

Viper venom

A viper's poison consists of a whole coctail of enzymes that break down the body in various creative ways. The primary toxin of most vipers is a hemotoxin. Hemotoxins attack the blood, either by making it clot inside the body, breaking down red blood cells so they spill their content into the plasma, or attacking the walls of the blood vessels to let blood leak through. The latter toxins are called hemmorrhagic, for they cause the victim to bleed internally leading to bloody urine, bloody spit, bloody stool, coughing up blood, and bleeding from the nose, anus, gums, eyes, and fingernails. The buildup of waste in the blood (from micro-clots or the blood cells' inside gunk in the plasma) can overload the kidneys as they try to filter it out. The blood is prevented from doing what it needs to do in the body, lack of oxygen leads to shock, and organs start shutting down. As the organs start to fail, the victim experiences nausea and confusion. The end result can be death. In game terms, this is treated as Cyclic damage with Symptoms and the No Crippling modifier to represent the systemic rather than local effect. Resistance rolls are allowed each cycle, but sucessfully resisting does not stop the cycles Another effect of a viper bite is destruction of the tissue immediately surrounding the bite location. Viper venom contains poison that directly kills cells, called necrotic or cytotoxic venom. The effects start off with swelling, bruising, and discoloration of the affected area. If enough venom is delivered, the tissue starts to die, forming blackened areas. If enough flesh is destroyed in this way, it can lead to permanent debility or even effective amputation of the affected limb as the dead meat sloughs off, leaving only the bone. This is normal damage, but cyclic, such that the wound develops over a few days. As with the hemotoxins, a resistance roll is allowed, but succeeding at a resistance roll does not stop the cycles. Unlike the hemotoxins, the damage can cause crippling or even dismemberment. One effect nearly universally observed from viper bites is immediate, acute pain, like being jabbed by a red-hot needle. The fiery sensation spreads with the venom, often leading to impairment from the pain alone. This effect is not usually given a technical name in the litterature (probably because it is caused by the same chemicals that cause the hemotoxic or necrotic effects), in this document it is called the algesic component of the venom in order to separate its effects from the rest of the venom. In game terms, this is damage with the No Wounding modifier, and the pain comes from shock penalties and pain-related Symptoms. The damage is applied only once at the moment of the bite, and lasts as long as the (non-wounding) damage has not healed past the point of no Symptoms. A very few vipers have neurotoxic venom. This venom attacks the nerves, leading to loss of coordination, drooling, sweating, nausea, blurred vision, dizziness, and paralysis. Eventually the paralysis reaches the diaphram and the victim suffocates. In game terms, this is damage with the No Wounding modifier, which causes its effects through Symptoms. The deadly effects are treated in game terms with the Choking Symptom, which as stated under the description of the Symptom modifier (pg. B 109) lasts as long as the damage remains over the threshold (1.5 × HP, in this case). If the bite victim is kept on mechanical ventillation, he can survive indefinitely - long enough to heal the damage - but if mechanical ventillation stops he will begin to suffocate again. First Aid can be used to give mouth-to-mouth to keep the victim alive until medical help arrives. Each component of the venom does damage separately, and each gets a separate resistance roll (exception: use the same resistance roll for hemotoxic, hemorrhagic, and necrotic venom effects since they tend to come from the same chemicals - but still roll damage separately). If the GM thinks it is worth it, he can have damage (and symptoms) build up gradually over the course of a cycle. For example, 5 points of damage in the first 10 minute cycle could be applied as 1 point every 2 minutes. The listed damage is for the entire dose of the viper's venom. As mentioned, however, vipers frequently only inject a portion of their venom, so as not to leave them vulnerable and unable to feed. Two-thirds of a dose does -1 point per two dice of damage. One third does -1 point per die of damage. One ninth of a dose does half damage. Two ninths of a dose does half damage plus 1 per die of the reduced damage. Any other amount will round down to the nearest listed damage. Assume snakes do not have enough control to inject less than 1/9 of their venom unless they deliver a "dry" bite (no venom at all, just a warning). If a snake has multiple kinds of venom, it must always deliver the same amount of a dose from each (i.e. if a rattlesnake with hemotoxic, necrotizing and algesic venom delivers 1/3 of a dose, it uses up 1/3 of its hemotoxic, necrotizing and algesic venom). (It usually will not matter, since each snake can only inject up to one dose at a time, but if a victim is subject to multiple doses - bitten by several snakes, for example - use the rules from monstersaurs for effects of several doses at once). Note - the peculiar way that damage changes with dose is so that venom damage scales properly with the size of the prey. A given weight of venom has the same effect for a given weight of envenomation victim, twice the weight of the victim requires twice the weight of venom. Since HP in GURPS scales as the cube root of weight, it follows that the damage caused by the venom must scale as the cube root of the amount injected. The above rules about dose size approximate this scaling. If a character is envenomated and rolls a critical success on his first resistance roll against that type of venom ever, he is Resistant. He has always been resistant, but just didn't know it until now. Write down on his character sheet that he has the advantage Resistant against that particular type of venom (specific to the genus, and the variety (neurotoxic, etc. - although you can lump necrotoxic, hemotoxic, and hemorrhagic effects of the same venom together). For example, Resistant (+8, rattlesnake hemotoxins).). The level of Resistant depends on the degree of critical success - making the critical success exactly is Resistant +3, making the roll by 1 is Resistant +8, and by two or more is full-on Immunity. This only happens the first time the character is exposed to venom of this kind. On subsequent critical successes on the resistance roll, the character's immune system reacts to the venom. He gets a similar level of Resistant, but it is temporary - the level of Resistant decreased by one per month (from Immune to +8 to +3 to no resistance bonus). This can be proplonged by further exposure to the venom - each exposure "resets the clock," so that effective permanent resistance can be obtained by the character regularly injecting himself with viper venom. Similarly, a critical failure the first time the character is exposed means the character has always been particularly susceptible to that venom. An exact critical failure is Susceptible -3, a critical failure by 1 is Susceptible -8, and a critical failure by more than that 1 is Susceptible -8 plus one level of Vulnerability. Subsequent critical failures represent an alergic reaction to the venom - an exact critical failure means penalties equivalent to Moderate Pain (actually itchiness, rashes, swelling and puffiness, dry throat and eyes, and difficulty breathing rather than actual pain). Critical failure by 2 or more gives anaphylactic shock - the same effect but accompanied by the Choking incapacitating condition (pg. B428). Surviving an envenomation is a good excuse to justify buying any level of Resistant to the venom the character was exposed to. The standard treatment for viper bites since the early 20th century is injection with an antivenom - antibodies for the venom extracted from horses that had been injected with extracted snake venom. This should only be done at a hospital by trained medical staff. If successfully applied, antivenom gives +8 to the resistance checks. There is, however, a downside - serum sickness. Make a HT roll, on a failure the character has an alergic reaction to the antivenom - treat this as Moderate Pain (pg. B428) except instead of actual pain the penalty is caused by itchiness, rashes, aching joints, fever, swollen lymph nodes, and general malaise. The effects begin 2d days after the first dose of antivenom and last for one day plus an extra day for every point by which the roll failed. On a failure by 5 or more, the character goes into anaphylactic shock within minutes after the dose is administered - treat as Choking (pg. B428). Choking can be stopped by a dose of Epinepherin, which may be carried by people with severe alergies but is otherwise mostly available at hospitals. The pressure immobilization technique that works for elapid venom does not work for viper venom. Nor do any "home remedy" treatments such as whisky, cutting and sucking, electroshock, hot or cold packs, or tournequets. These do no good, and can cause additional harm. Get the victim to a hospital as quickly as possible and the prognosis for a full recovery is good. The potency listed for viper toxins are merely suggestions. While based on the best values I could find for lethal dose and venom yield, toxicity of venom varies considerably from species to species and even from population to population, individual to individual, the time of the year, and the animal's physiological sate. Also note that toxicity is not consistent across listed viper types, but is weighted by typical values for that type - so that two different vipers with the same weight, venom potency, and venom composition can have different venom damages because, for example, rattlesnake venoms typically measure higher in toxicity than lancehead venoms.

Game Statistics

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