These tokens represent an investigator’s training
in particular skills. When an effect allows an
investigator to improve a skill, he gains an
Improvement token with the matching icon and
places it below his Investigator sheet with the “+1” side up.
If he improves that skill a second time, he flips that token to
the “+2” side. An investigator’s skill is equal to the value printed
on his sheet plus the value of the matching Improvement token.