[Relaxing]

This checks whether the cvar is 1 or 0,
1 on true statement, 0 on false.
If you want to block the deathmatch cvar just delete the if statement, respawn_player_task func. and the cvarS.

Using const integers you can't change the value of it, since const is used & in this case it will be always deathmatch.

For multiple mods you can use if (get_pcvar_num(cvar_deathmatch) ==1 / 2 / 3 ...) depending on the amount of gameplays you want to add.