Thread: BD vs Killers

Hello reader,

i need to know how to play the a custom map/addon made by someone in Left 4 Dead 1, because in Left 4 Dead 2 it's simple: You go into ''Extras'' and then it says ''Developer Commentary, Credits, Addons'', while in Left 4 Dead 1 it only says (in the extras): ''Developer Commentary, Credits''.

Can you please tell me how i can play addons in Left 4 Dead 1, or if i even can?

Thanks, and you can tell i'm not very good at this