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NO friendly fire

NO friendly fire. The damage values are set to zero.
Setup: just start a lobby and pick NO friendly fire under challenges.

Commands used

asw_marine_ff_dmg_base 0
asw_marine_ff_dmg_step 0


Because some one asked:
"""
how to use it?
sv_cheats 1
asw_marine_ff_dmg_base 0
asw_marine_ff_dmg_step 0
map xxxxx
but my firend cant join my game
"""
The commands above are not needed if you use this add-on as a challenge, but I gave the Commands to you just in case you wanted to use them.

There are 4 ways to use NO friendly fire.
Way One: Add-on

Just subscribe to add-on, start the game, at main menu click play online, create game, go to challenges, select NO friendly fire from list, create game, and online lobby should be up and working with NO friendly fire.

Way Two: Hosting a Local (Listen) using sv_cheats 1

This is harder and may not always work.
Pre-Info

port forwarding - NOTE: some times listen servers will run with out forwarding and sometimes they will not work unless you port forward. So you can try and if it fails to run you can port forward .
More info on ports and Hosting a Local (Listen)
Required Ports for Steam
Hosting a Local (Listen) Server for Valve Games

setup

map asi-jac1-landingbay_01
heartbeat
net_start
net_status
heartbeat
sv_cheats 1
asw_marine_ff_dmg_base 0
asw_marine_ff_dmg_step 0
sv_cheats 0

Those should work, but if no one can connect try port forwarding

If port forwarding did not work try command below

ip xxx.xxx.xxx
the X is your external IP

Still not working, then something is going on and you'll need to troubleshoot and search for like issues on internet

Way Three (way I did): Hosting a Local (Listen) using sourcemods so sv_cheats runs at server start


There's lots of guides on this already
If you want to go the sourcemods way look for a guide on running Console Command/Cvars at server start
https://www.sourcemod.net/


NOTE this should work with out having to make a Local (Listen). You should be able to go to main menu click play online, create game, and online lobby should be up and working. I have not not tried in some time so it may have changed and not work anymore, but give it a go.

Way four: dedicated server
haven't done one, but it should be like way two with extra steps. You would need to download the dedicated server tools.

Extra Resources:
List of Reactive Drop Cvars
Console Command List
Command Line Options