Goodman Games

I don't think this answers my question. It covers what happens after a character has become engulfed but not how the initial engulfing occurs. Is it simply an action roll that the elemental takes that needs to roll higher than the characters armor class? I feel like my players are going to ask to ma...

In an upcoming adventure the players are going to encounter a water elemental that attacks with engulf. I can't find the rules for engulf in the core book or in the monster's stat block. I am guessing it's something like a reflex save to avoid, so I could just make up a number that seems appropriate...