Have you ever wondered if there was an Intellect Devourer inside the goblin you just slayed? Or the merchant you just met? Or the trustworthy looking PC that has just joined you? Well, now you do.
With the help of this highly scientific formula*, you can calculate the odds of any of those eventualities. Consider any discovered Intellect Devourers as bonus loot (that wants to eat your brain), or a twist in the plot (that will end up eating your brain), or a way to get swanky psychic powers (in exchange for your brain).
Intelligence save Proficency bonus:
Number of rounds the creature interacts with an Intellect Devourer:
Illithid Infestations (per square kilometer):
Average population of Intellect Devourers maintained by each illithid infestation:
Typical roaming distance of an Intellect Devourer (in kilometers):
Distance to the nearest underdark entrance (in kilometers):
Typical roaming distance of the creature in question (in kilometers):
Average turnover rate (how many days it takes for an Intellect Devourer to be discovered or move on from its host):
Illithid Activity – a scaling factor, entirely up to GM:
Intellect Devourers met: