Poison

"You're poison, running through my veins!"

– Alice Cooper

Poison is any substance inimical to life. This applies to obvious stuff like snake venom, also to overdoses of vital medicine (often designed to kill bad life, like parasites). The dose, as they say, makes the poison.

In Dungeons & Dragons, poison is often used in traps, causing damage or death - one more reason that Rogue you brought along isn't going to last through your first adventure. Plenty of monsters have poison too, from the lowly spider to the mightiest Nightshade.

Classically, the "Save Versus Poison" was one of the low-rollers, compared to (say) Versus Spells; so the Rogue does have a chance with the russian-roulette. Just not as high as his/her player would like. We recommend going a little easy on the type of poison for low-level adventurers because killing a character for doing That One Job is a cock move.

Much ink has been spilled over whether player characters get to use poison too. The consensus is: no, because when the goblins find out they'll be uninclined to mercy if they ever meet you afterward.