code/__DEFINES/projectiles.dm

PROJECTILE_PIERCE_NONE	Default behavior: hit and delete self
PROJECTILE_PIERCE_HIT	Hit the thing but go through without deleting. Causes on_hit to be called with pierced = TRUE
PROJECTILE_PIERCE_PHASE	Entirely phase through the thing without ever hitting.

Define Details

Hit the thing but go through without deleting. Causes on_hit to be called with pierced = TRUE

Default behavior: hit and delete self

Entirely phase through the thing without ever hitting.