11-9=3

A group of college friends went to explore an abandoned forest which is said to be guided by many spirits. The spirits usually stay at a place. They can be creepy as well as not. The forest has many zones. The primary zone, the orange zone, and the skull zone. Every zone has a rule which must be followed, or in other words you are welcomed by "them".

Primary zone.
This zone is quite normal, still not. You will feel quite normal, however in some point you will feel lost at times. You might feel stared or so. Once you entered this zone, you must not go out or just roam once the sun is set.

The orange zone or the devil's neighbour.
Its like seating in a carnivore's back. You can't stay for too long or once you are out of its back- you're dead. In this zone you will feel guided by some sort of extraordinary intuitions. But the most death occur in this zone. It has a simple rule, "play or die".

The skull zone or the devil's home.
Its quite simple. You don't have to worry about the place, but yet you have to. There would be trees covered with skulls, some cannibals out there will be vibing, there would be pieces of human meat strangling in trees. Its said that only 2 animates can leave the place after reaching this zone. It has the most simplest rule, just have a cup of tea with a unidentified creature.

So far 11 people went. But 2 humans came back, however in this plot 11-9 =3.
9 dead? But it's 3? Is it a-

Better luck next time honey ;)

Pick one character :)