We have two players, Alyx and Michaela. We also have three monsters, a Magma Fanged Deer and a Slime Wolf which was hunting the deer, as well as a Changeling Assassin who triggered a fight between the two animals so that the players would be in the middle of it, while they sneak around behind the players.
DM: Alyx and Michaela, your two characters hear a snap that sounds almost like a fire cracker, and you see yourself surrounded by a Fanged Deer, with burning red eyes, and fire sprouting from its hooves. The other side is a translucent wolf, looking like its made from a blue gelatin with wisps of tentacles coming out of it as it bares its fangs.
Alyx: I want to be ready to dodge out of any attacks.
Michaela: Can I tell if they are going for each other or us? Why are two different animals attacking?
DM: Okay, Alyx, you do a Dodge action, you get back the energy if you don't use it before your action expires. Michaela, give me an Awareness check.
Michaela: Actually dodging is also a good idea, so I'll use it as a plus action with the Defense action.
DM: Sounds good. Roll initiative after that.
Michaela: Okay, does Beast Mastery help me here?
DM: Not for this. But take a circumstance bonus if you have Natura or Survival.
Michaela is using her Awareness skill. As a martial, her base die for that skill is a d12, she also gets 1d8 (Skill), and 1d4 (for having Survival training). They get a 1 on their base, and a 4,1. They take the 1+4 and get 5.
Michaela: I got a 5.
DM: Did you add your Experience?
Michaela: Oh, no, is there a level difference?
DM: Yes, the animals are 2 levels lower than you.
Michaela: Okay, so that is 2+2, so 4, then 5 is 9!
The animals are pretty base, and they are obvious in what they are doing. The DM thinks that since the cause of the actions is from the assassin's trick, they will do a contested stealth check to set the DC. DM rolls a skill check for the subterfuge of the assassin, and like Michaela, they fumble the roll with a 1! The assassin is using a stealth check with a subterfuge, and a tool bonus to circumstance (a firecracker). They roll a 5,2,4 and have a Flat 2 (equal level to the players). That totals 8 (1+5+2)!
DM: The noise you heard triggered their fight or flight, and it looks like they chose, fight. You can tell that someone set it off, and they must be nearby. Lets get those initiatives going.