How to change difficulty and enable friendly fire?

[Demie]

Hello!
I want to play hl1 with a friend, but 1. the game is too easy, and 2. there is no friendly fire, which makes the whole experience have no stakes and feel rather bland.

Is there a way to enable/change those things?

[John Henry Eden]

https://steamcommunity.com/app/225840/discussions/0/1638662230360352890/