This trick is possible with two to four players. While in the lobby, have someone change to any character except for random or infected. Then, have the others change to infected. Have the person on survivors go to "Change Character" and highlight the "Infected" option. Start the game and have the person switch to infected before the game finds a dedicated server. The game will start but there will be no one on the other team. It will take about two to five minutes before the NPCs open the door and leave the safe room. Note: If you kill the survivors or the survivors win, the game will not end. If someone joins the other team, it will be fixed and the game will continue. This glitch only works on the first levels of Blood Harvest and No Mercy.