I very rarely make posts about game mechanics, but there’s something I’ve started thinking about recently: poison! How does one make it engaging? I don’t really like Save or Die type poisons and I haven’t given any Vaarn monsters this ability. The closest is the Amaranthine Death-Worm, which can inflict you with a special status that prevents your HP from being higher than 0. Nasty! But not instant death. However, most creatures aren’t as venomous as the Death-Worms are, and I want their ability to be a unique one.

The obvious solution is to make less potent toxins and poisons a Damage Over Time (DOT) effect. I like DOTs in theory, but I’ve been struggling to come up with a way of tracking the DOT that doesn’t put loads more mental strain on me as a GM. Videogames can easily apply an effect that does X amount of damage every round for Y rounds. When I write stuff like that and try to run it myself, it’s a hassle for me. I end up with another little bit of book keeping each combat round, remembering to deduct HP from the players affected, keeping track of how long the effect has been active, and god forbid the monster poisons the player again two rounds later and gives me another new asynchronous DOT countdown to remember. It’s a mess, frankly, and distracts me from more important stuff like clear descriptions, varying the monsters tactics, re-iterating everyone’s positions, making sure the battle is dynamic, remembering to do Morale checks, etc.

My solution is simple: apply the Usage Dice rule to DOTs. Basically, Vaarn PCs can incur a Toxin Dice, which represents their exposure to venoms, poisons, radiation, etc.

Toxin Dice go in a chain, which looks like this: d4 – d6 – d8 – d10 – d12 – d20. Nothing new here if you’ve seen a dice chain before. If you have a Toxin Dice sat on your character sheet, you have to roll it every time your combat round comes up, and subtract the result from your HP before you act. If the result of your Toxin Dice is four or lower, the TD steps down one dice size in the ladder. If not, it stays the same size. The rung below d4 is 0, so once you roll a d4 you’ll be cured of whatever is ailing you.

Getting hit again by a new toxic attack steps your TD up, but only to the maximum TD level listed next to that attack. So if my Toxin Dice is a d6, and I get hit by a d8 Toxin attack, my Toxin Dice steps up to a d8. If my Toxin Dice is a d12 (!) and I get hit by a d8 Toxin attack, my Toxin Dice doesn’t change. This puts a bit of a cap on toxin damage, so less venomous creatures can’t bump you up to the d20 damage threshold (which is nasty). Obviously if you want to be a real asshole you could have stacking Toxin Dice from different toxic attacks, but this could kill PCs really fast if they’re rolling three or four d8 TD each round.

If you’re outside combat, then roll the TD every time the GM would check for random encounters.

Why bother with this? It solves the problems I had with DOTs: it’s easier to remember (because the dice are right in front of each player affected) and it’s more interactive (because they have to roll the Toxin Dice and interpret the results themselves). It also simplifies the problem I had with new asynchronous DOT countdowns being started: the new toxin damage just bumps the TD back up to its original size. If I were embracing this system I might even buy special dice to be the Toxin Dice, and have ones that are yellow and black or like lurid green or something.

I used this system in my players’ encounter with the venomous glider-spiders in our last Vaults session, and it worked well. I do it all via video chat so I didn’t actually explain the system to them during the fight, but it let me easily track the poison damage on each PC throughout the combat. There are other fun wrinkles you could add, like psychic toxins that only roll for damage when you use Mystic Gifts, or language viruses that make the character roll their TD whenever they speak out loud, and so on.

Anyway, just a thought. I’m going to keep using this rule and see how it plays long term.

10 thoughts on “TOXIN DICE”

  1. I like the idea of this mechanic for DOT, but as I was reading this post I was thinking that if PCs can be poisoned or have other DOT effects, wouldn’t the PCs also have the ability to inflict DOT to NPCs and Mobs? And if so, wouldn’t the Referee still need to track these toxin die along with all the other referee things?


    1. Yes, they would. It certainly isn’t a system without any extra GM overhead – it does create a new combat element to keep track of. So if you favour absolute simplicity in these matters, it doesn’t suit.

      My thinking was (a) to make the DOT system tactile, by using physical dice as markers, because this helps me keep track of the status effect and (b) try as much as possible to involve the players in tracking DOT damage, rather than leaving it solely to me. That’s why I specify putting the Toxin Dice right in front of the afflicted player.

      In the case of PCs poisoning monsters, I’d be happy for them to do it – so long as they remind me to roll the Toxin Dice for that monster when the monster turn comes around. I find players are usually very attentive to anything that would give them an edge in combat, so they’ll be unlikely to let me forget about the TDs they’ve inflicted on the monsters.

      I also limited the TD to one per entity to make it a bit cleaner. But yeah, it is more mental load. I want to test it further with my Sunday group and see if it continues to hold up, and if so the system will make it into a future zine.

      Liked by 1 person

  2. Really enjoyed this post. I love certain board games for their intuitive and logical mechanics. This checks both boxes! Such a great way to offload work from the GM and give the player something most players like doing – rolling dice.


    1. Thanks, I can’t really take credit for the idea as I’m sure others have had it before me. But I was thinking about the usage dice concept one day and realised it could be used for incremental DOT effects as well as tracking supplies. The Ikor Quag zine will feature quite a few poisonous monsters so I’m thinking now about how best to present that in gameplay.


  3. I wouldn’t use a d20. Rather I would use my Dungeon Crawl Dice and have the chain d4-d5-d6-d7-d8-d10 and maybe add in d12 and d14 for the really lethal critters.

    Otherwise, awesome idea for damaging types of poisons. I tend to go with curses or strange symptoms to make my venomous creatures different in play, but this does work well for some types of monsters and player interaction.


    1. Yeah the d20 might get a bit goofy, I think this would be a good opportunity to use the zocchi dice.

      I think there’s definitely an argument for coming up with unique poison effects for the creature if you can think of one that makes sense, strange symptoms and slowly spreading ailments are awesome in my book. But sometimes you just want a DOT to tick each round and put the pressure on.

      Liked by 1 person

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