In old school D&D when you got bitten by something poisonous you saved vs poison. If you failed, in most cases you died right there on the spot.

It was wonderfully brutal and forced players to avoid directly battling creatures that were poisonous and to be very careful around things like chests that might have poison darts or traps that might have poison spikes.

Poison was deadly.

If you want a ‘funnel’ style adventure save vs poison or die is fantastic but you really need a plan for when characters die. Character death can be really boring for the player who dies.

Strategies include NPCs a player can immediately start playing or new player characters already rolled and ready to go who appear more or less immediately when a PC dies.

If rolling up a new character is fast, players can immediately start rolling and once they’re finished they can rejoin the action as a character who just made it to the party, sent as a reinforcement from their home base.

In funnels it’s also standard for other player characters in the party to loot the body of the dead player character.

My favorite for poisoning is needing an antidote before the end of the session or they die, or needing an antidote before the end of the next session if they get poisoned right near the end of a session. Then finding an antidote becomes the key quest the party has to complete.

To make it more interesting roll an attribute randomly and any action using that attribute is now at disadvantage for the poisoned PC. Every hour roll for another attribute and that’s at disadvantage too. This gives the party the fun of dragging around a PC who can do some things and not others and is deteriorating.

This is only appropriate if the party actually cares about the character. Also getting the antidote shouldn’t be easy. It should be somewhere that’s a real challenge to get to or create some other serious challenge. It could even be a moral problem.

“The good news is I know where to find an antidote.
The bad news is, it might not be that easy to get to it.”

Ultimately what I try to shoot for is player agency. Players get to choose what they do and being poisoned can create a fun adventure to get the antidote or the poisoned PC can choose to go down fighting finishing whatever quest they’re on.

This concept also works well in solo play. Killing off your player character with poison when you’re playing solo can be boring and disappointing but going on quest for an antidote before you die at the end of the session is exciting.