Idiot Savant

Idiot Savant is a perk in Fallout 4.

Effects
For ranks 1 and 2, the perk randomly activates whenever one gains experience from any source. At 1 Intelligence, the chance of activation is 11%, and one loses 1% per added point of Intelligence. The chance minimizes at 1% at Intelligence 11 or higher.

When the perk activates, a laughing Vault-Boy appears above the compass, and one of several possible laughing sounds are heard. The experience that would have been earned will instead be boosted to 3x (for rank 1) or 5x (for rank 2+). This boost is multiplicative with any normally additive experience bonuses from being Well Rested or having a high Intelligence.

The probability for the "kill bonus" from rank 3 appears to be independent of the bonus experience from rank 1 and 2 and the probability of it triggering is currently unknown. The effect lasts 60 seconds.

Comparison to Intelligence

 * $$IntMulti = 1 + (Intelligence \times 0.03)$$


 * $$AvgIdiotSavantExpMulti = 1 + \Bigg(\frac{min(2,IdiotSavantPerkLevel) \times %Chance}{50}\Bigg) $$


 * $$OverallExp = IntMulti \times AvgIdiotSavantExpMulti$$

When comparing a perk point to put into higher Intelligence or Idiot Savant, one can compare benefits above. Each point in Intelligence improves experience gain by 3%. Consulting the above table, it can be seen that with two levels of this perk, average experience gain is optimized at 2 INT and actually drops with each additional Intelligence point until very high levels of Intelligence (15+).

Behind the scenes
The term idiot savant is an obsolete term in psychology for Savant Syndrome, where a person is mentally challenged due to neurological disorders or brain injuries, but displays exceptional skill in a specific field such as art, arithmetic, music, or memory, far beyond what most neurotypical people can accomplish, such as recalling specific dates and times or re-playing a piece of music perfectly on piano after hearing it only once.

Bugs
If the Idiot Savant perk activates when turning in a quest, you will sometimes not get the 3x or 5x multiple of experience points.

Savant idiot Савант