Intelligence represents how well investigators learn, remember, and analyze, and of how aware they are of that which is around them. To help describe different circumstances, keepers multiply INT times various numerals and then call for D100 rolls equal to or less than the products. INT x5 – the idea roll – is especially popular. For more about it, see further below.
Difficult concepts, plans, or inspired guesses have lower chances to be derived, and hence get lower multipliers, down to INT x2 or INT x1. Such rolls cna establish whether or not an investigator makes a deduction or links information, avoiding the question of the player deducting (for instance) that the presence of a volcano argues that a world has a molten core.
An investigator without INT is a babbling, drooling idiot. Intelligence determines the number of personal interest skill points allotted to a new investigator, and also how quickly can investigator can learn Cthulhu Mythos spell.
If the amount of intelligence seems to contradict a characteristic rolled later, that’s another chance for roleplaying: an investigator with high EDU and low INT, for instance might be a pedantic teacher or a sideshow performer, someone who knows facts but no their meanings. Conversely, hight INT and low EDU might mean ignorance – a farm boy or poor immigrant, new to the Big City 0 but this person would not be dull-witted.