Just a quick and simple plugin to allow clients to change their FOV. I couldn't find another so I made my own. CS has FOV locked to 90 by default, which is not ideal for modern monitors, especially since the GoldSrc engine is Vert-. Plugin is for CS, but should work in other mods, or should be easy to adapt to work.
To use, open console and type
fov 105 which would be good for most modern monitors, or whatever value you wish between 90 and 180. You have to do that after each map change, so it might be best to bind it to a key like
bind p "fov 105" for easy access.
Code is based on this plugin from ConnorMcLeod :
default_fov . What I changed was to make it possible for each client to set his FOV individually, the original plugin had it as a global server-side setting, which didn't take into account that different players have different monitors.