|Raiders of the Lost Ark - Paramount Pictures|
"Snakes. Why'd it have to be snakes?"
"Asps. Very dangerous... You go first!"
I was researching snake venom recently (as part of my ongoing effort to make my search history as incriminating as possible) and decided snake venom in Pathfinder needed to be revised. Venomous snake bites in Pathfinder all have the same effect - Constitution damage. In reality, venomous snakes bear neurotoxins that slowly paralyze their prey, hemotoxins that cause tissue decay and uncontrollable bleeding, and mixes of the two, with dendrotoxins and cytotoxins and other heinous crap thrown in for good measure.
Dexterity damage seems like a good choice to simulate neurotoxic paralysis, and Strength damage and Bleed work well for Hemotoxins. A few choice status effects like 'sickened' and 'nauseated' serve to simulate the wide range of other symptoms snake bites can induce, including rashes, dizziness, tunnel vision, soreness, and, of course, nausea.
Snake venom is slower-acting and longer-lasting than what the viper stat block would have you believe. I made the frequency for most snake venoms "1/minute" instead of "1/round", but where many snake venoms may last "for six rounds", my venoms are endless. You gotta make those saves or you will die ...eventually. That means a fight against snakes at the dungeon entrance might still be affecting you deeper in the dungeon.
There are two main types of venomous snake: vipers, which include rattlesnakes, adders, and pit vipers; and elapids, which include cobras, coral snakes, mambas, kraits, and sea snakes. Elapids tend to have neurotoxins, with the more dangerous ones (black mambas, for example) having a sprinkling of other toxins. Water snakes are neurotoxic, but because you are most likely to encounter them while swimming (a Strength-based skill), I made their venom deal Strength damage to heighten the danger. Vipers, on the other hand, usually have hemotoxins. Hemotoxins are slower-acting than neurotoxins (I gave them a frequency of 1/hour instead of 1/minute), so vipers tend to strike and fall back, tracking down their victim later, after they have succumbed to the poison. Fun fact: vipers can track their prey by the smell of the chemicals in their bites. Scarier vipers, like the mojave rattlesnake, also have neurotoxins in their bite.
I've also added a new mechanic to add variable degrees of failure to saves against venom. Now, if you fail your save, you take the venom's effects, but if you fail your save by 5 or more, you take a worse set of effects. For instance, a coral snake's venom deals 1d2 Dex damage, but a failure by 5 or more leaves you paralyzed until your next save.
Enough discussion. Like cardiotoxin, let's get right to the heart of the matter.
The following rules and poisons in gold are available as Open Game Content under the OGL. Open Game Content is ©2015 Jonah Bomgaars and d20 Despot.