Basically, the rules are simple. The poster above you says "In case of Emergency", and you say something from a scenario thats remotely funny. You can replace "Emergency" with anything, by the way.

So essentially, to start off, its like this:

Me: In case of Emergency...
~~~~~~~~~~~~~~
Random poster below me: Call for Chuck Norris.

Random poster below me: In case of Chuck Norris...
~~~~~~~~~~~~~~
Me: Run like hell.

Me: In case of Zombie Apocalypse...

Ect ect.

So, here I go.