There is a Legacy version here.

Splash

Source GM Core pg. 244
Most bombs also have the splash trait. When you use a thrown weapon with the splash trait, you don’t add your Strength modifier to the damage roll. If an attack with a splash weapon fails, succeeds, or critically succeeds, all creatures within 5 feet of the target (including the target) take the listed splash damage. On a critical failure, the bomb misses entirely, dealing no damage. Add splash damage together with the initial damage against the target before applying the target’s resistance or weakness. You don’t multiply splash damage on a critical hit.