If you've got the 'only four campaigns in Left 4 Dead' blues, we might have found the solution for you.

Modders in the Steam community have managed to work out a way to play Left 4 Dead on a variety of previous Valve games, including Team Fortress 2 and Half Life 2.

Left 4 Dead - Screenshot 2534

Soon you could be blasting Boomers on the streets of City 17

But these are no mere file rips - you can actually play through maps from the Valve games as if they were real L4D maps, with the AI director working fully.

Not convinced? Take a look for yourself as one modder takes on the zombie horde that have infected Team Fortress 2's 'Dustbowl'.

Or how about ploughing your way through the Nova Prospekt zombie apocalypse?

For all the information you need to join in the fun, check out the Steam forum post concerning the steps needed.