Starfield Skills -> Combat Skills
Shotgun Certification is a skill in Starfield located in the Combat skill tree that improves player damage with Shotguns.
Shotgun Certification Skill Description
The cornerstone of close quarters combat, or CQC, the shotgun has proven a simple, deadly weapon for hundreds of years.

Shotgun Certification Skill Ranks
Rank 1
Shotguns do 10% more damage.
Rank 2
Shotguns do 20% more damage.
Rank 3
Shotguns do 30% more damage.
Rank 4
Shotgun kills grant a small chance to Stun additional targets with shotguns for a limited time.