10 MORE Video Games You Didn't Know Were Connected

10. Dead Rising/Left 4 Dead

The Left 4 Dead franchise is an utter goldmine of sneaky Easter eggs and references, and while the majority of these nods are pretty throwaway, there's one that connects the co-op zombie series to its undead brethren, Dead Rising, with an elegant simplicity.

In Left 4 Dead 2's DLC campaign "The Passing", one of the safe houses has graffiti scrawled by a familiar name.

It reads, "Otis, out of film, no helicopter. Zombies are too fast. Not going to make it", signed by Frank West, who was of course the protagonist of the first and fourth Dead Rising games.

Roughly a year later, Dead Rising 2 returned the favour with its "Case West" DLC, where players could find the phrase, "Don't startle the wi-" written in blood in an underground tunnel beneath the Phenotrans Facility.

The "wi-" is a nod to the Witch enemy from Left 4 Dead, which upon being startled by the player can dole out an insta-kill.

Between these two well-placed tips of the hat, is there any dispute that these games reside within the same universe?