Favourable Beginnings is a passive feature and Illithid Power. This feature applies a character's Proficiency Bonus to the first Attack Roll or Ability Check made against a target.
Description
The first 
Attack roll or 
Ability check you make against any target gains a bonus equal to your Proficiency Bonus.
How to learn
Used by creatures:
Other ways to learn:
- Unlock from the illithid power skill tree with a Mind Flayer Parasite Specimen.
- Unlocked automatically after becoming a Partial-Illithid
Bugs
- Contrary to the description, only Deception and Persuasion receive ability check bonuses.