List of references

Within Portal 2, both in-game and in the trailers, are multiple references. There are a variety of references, mostly including games or parts of games.

General References

 * The achievement, Schrodinger's Catch is a reference to Schrodinger's Cat, in which Schrodinger exposed radiation to a cat inside a sealed box. His theory dictates that the cat is both alive and dead while the box is sealed.

Left 4 Dead series

 * During one of the pre-release trailers, Atlas can be seen wielding the frying pan, a weapon used by the survivors in L4D2.

Smash TV

 * One of the achievements labeled Smash TV is a reference to an early 90's arcade game called Smash TV, where two contestants are pitted in a brutal game show in which they're forced to fight for their lives for cash prizes.

Movies

 * The achievement Stranger Than Friction is a reference to Stranger Than Fiction', in which a man finds out his life is being narrated like a novel.