What is iocane?

Iocane is a fictional poison from the 1987 film "The Princess Bride." It is described as a colorless, odorless, and tasteless substance that is deadly when ingested. The character Vizzini famously uses it in a battle of wits against Westley to determine who will drink from a cup laced with the poison. Iocane has since become a popular reference in discussions about clever tactics and strategic thinking.