Double Melee

The double melee is a glitch that allows survivors to melee two times in extremly quick sucession.

How to Do the Double Melee
By pressing the melee button and the change weapon button in rapid sucession, the survivor will melee extremely quickly, and does not have to stop. This is extremely effective when being surrounded by a horde, or when ammo is scarce as the double melee will kill many infected rather quickly.