The first question that every new mapper asks is always the same: "How do I run a .bsp I just downloaded?"
Fortunately this is quite a simple process, but it is slightly different depending on if the map is single player or multiplayer.
Where to put BSP files
Whether the map is single player or multiplayer, it must be put into the
folder of the mod. This is a standard location in every mod folder, some examples:
<steam install folder>/SteamApps/common/Half-Life/valve/maps
<steam install folder>/SteamApps/common/Half-Life/cstrike/maps
- Sven Co-op (Steam):
<steam install folder>/SteamApps/common/Sven Co-op/svencoop/maps
Drop the BSP file directly into the
folder. There should be no subdirectories. The map may come with a text file with the same name as the map file, this is the "map information" file that shows in-game and is optional.
Some maps will also contain wad files, models, sounds, and other things. This is usually provided as a folder structure, you should be able to work out where to add the folders to in order to get them placed correctly. If in doubt, look for a readme file or ask the author for installation instructions.
Single player maps
To load a single player map, press the
key in the game to open the console. Type
into the console and press enter. Of course, you should replace
with the name of the BSP file you downloaded, without the .bsp file extension.
To load a deathmatch (or Counter-Strike) map, click Create Server
in the game's menu and select the map from the drop down list. Then just click Start
and you're done!