On Conga Lines and Triggering Traps
When exploring a dungeon, one of the ever present dangers is the potential existence of traps. One interesting bit of Old School Wisdom that I have discovered is that traps normally have a 2-in-6 or 1/3 chance of going off whenever someone passes by the trigger. I personally think that this is a very neat feature, but it raises the question of determining who gets affected by a trap. One person? Just roll a d6 and look at the numbers. But what about when you have a long line of explorers? It isn't uncommon for adventuring parties to bring along lots of help or befriended monsters, so the number of people passing by a trap might be quite large indeed. Slowing down play to roll a d6 for every creature passing the trigger is inefficient, so I started looking into alternatives. Due to quirks of probability, while the first person in line will have a 1/3 chance of triggering a trap, the person behind them will only trigger the trap when ...