Source-checkedGameplay & overhauls

Left 4 Bots (Improved A.I.)

by smilzo · for Left 4 Dead 2

This addon improves the survivor bots behavior to make them more human-like and a bit more useful during the game as well as improving their combat skills. It is a mix of vanilla AI improvements (via…

743KDownloads
2 yr agoLast updated
Steam WorkshopSource

About Left 4 Bots (Improved A.I.)

From Steam Workshop

This addon improves the survivor bots behavior to make them more human-like and a bit more useful during the game as well as improving their combat skills. It is a mix of vanilla AI improvements (via…

This addon improves the survivor bots behavior to make them more human-like and a bit more useful during the game as well as improving their combat skills. It is a mix of vanilla AI improvements (via game convars changes) and new features added via vscript.

Main features

  • Survivor bots can pick up and use defibrillators
  • Survivor bots can pick up throwable items (pipe bomb, bile jar and molotov) and throw them when needed (sometimes they will fu** it up, i warn you lol)
  • Survivor bots can pick up and deploy upgrades
  • Survivor bots can pick up and use melee weapons and the chainsaw (for M60 and GL you need to add the addon BOTS T3 or any other similar addon)
  • Survivor bots pick up med items more efficiently without waiting for humans to pick them up first (no more medkits left behind)
  • Survivor bots can scavenge and pour gascans and deliver cola bottles
  • Survivor bots can continue the map by themselves if you die (not all maps). Don't expect them to complete an expert campaign though
  • You can play a singleplayer versus match and practice as infected against a full survivor bot team (granted you enables the addons in versus mode in the game's "addonconfig.cfg" file)
  • You can order survivor bots to press buttons, open doors, activate things, pick up weapons, use the minigun (in The Sacrifice finale you can tell them to activate the generators all together so you can get the "Chaos Generator" achievement in singleplayer and you can also send bot Bill to the sacrifice generator for the "Kill Bill" achievement. It is also possible to get the "Sacrifizzle" achievement in singleplayer if you enable addons in versus mode)
  • You can order survivor bots to hold their position
  • You can order survivor bots to crown a witch
  • You can order survivor bots to lead the way to the saferoom (can be useful when playing a custom map for the first time and you can't find the path to the saferoom)
  • You can order survivor bots to heal themselves or to heal you or another team member
  • You can order survivor bots to throw their nades
  • Survivor bots will not heal themselves if they have 50+ HP (like they do in the start saferoom) unless there are enough medkits around for the teammates who need it and the bot to pick up after healing
  • Survivor bots will try to dodge the spitted spitter's acid
  • Survivor bots will try to shoot and destroy the tank's rock
  • Survivor bots react faster, aim better and will try to help more (not always with success though)
  • Survivor bots can startle witches (by accidentally shooting them) and set off car alarms just like the human survivors (if you want)
  • Survivor bots can give their items to human survivors when they aren't in fight
  • Human survivors can give their throwable items to any other survivor just like they do with pills and adrenaline
  • Human survivors can swap their throwable items with a survivor bot (you just give them your item to receive theirs back)
  • Last survivor bot entering the saferoom immediately closes it
  • Other features and more details can be found in the RELEASE NOTES

You can customize the vscripted features as you like by changing the ADDON SETTINGS ingame via chat command "!l4bsettings [setting] [value]" or by manually editing the file "Left 4 Dead 2\left4dead2\ems\left4bots\cfg\settings.txt". Vanilla AI features are improved via game convars changes (like many other AI improvements do) that are loaded from the file "Left 4 Dead 2\left4dead2\ems\left4bots\cfg\convars.txt". You can edit this file as you like or you can disable it in the settings. Bot orders can be issued via CHAT COMMANDS. Most commands are also bound to a vocalizer line. You can change the bindings as you like by editing the file "Left 4 Dead 2\left4dead2\ems\left4bots\cfg\vocalizer.txt".

NOTE: The addon configuration files are re-loaded at the beginning of each map/chapter so you can edit them without the need to restart the game/server.

This addon is fully compatible with LEFT 4 FUN, LEFT 4 GRIEF and the current version of the Rayman1103's Admin System. It is also compatible with sourcemod (some plugins may be incompatible though) and most of the other AI improvement addons (the convars ones, like Improved bots (simple), Competitive-bots+ and such. If you use those addons, just disable the L4B convars by setting the "load_convars" setting to "0").

PLEASE NOTE: THIS ADDON CANNOT TURN THE BOTS INTO PRO PLAYERS! The addon does not (it can't) replace the vanilla AI, it just adds features to it. This means that most of the issues that affect the vanilla AI will probably still be there even with this addon installed. Sorry but this is all i can do.

How to install

All you have to do is to subscribe to this addon, subscribe to LEFT 4 LIB (mandatory) and you are done. For dedicated servers simply upload the two .vpk files into the server's "Left 4 Dead 2/left4dead2/addons" directory and the local "admins.txt" file into the server's "Left 4 Dead 2/left4dead2/ems/left4bots/cfg" directory (see below).

Read the full description on Steam Workshop →

Highlights

From source data

Footprint

Rated a light load on a server.

Last update

Its author last shipped an update 2 yr ago.

Left 4 Bots (Improved A.I.) on Nxeon

From our catalogue
One-click install
Supported on Nxeon Left 4 Dead 2 servers. We download it from Steam Workshop, place it, and restart the server.
Server load
light
Latest build
2024-06-09, released 2024-06-09

Game versions by loader

LoaderGame versionsNewest
Workshop

From 1 recorded build of Left 4 Bots (Improved A.I.).

Dependencies

Declared by the newest build that lists any. Required ones are installed with it on one-click installs.

What kind of mod it is

From the catalog
Listed on Steam Workshop as “Workshop”

Gameplay & overhauls

New mechanics, content and overhauls that change how the game plays.

Compatibility

Game
Left 4 Dead 2

Verified at the source

  • ✓Steam WorkshopOfficial listing, checked 2026-11-01Open ↗
  • ✓Authorsmilzo, as published on Steam Workshop
  • ✓LicenseNot published by the sourceFree

Left 4 Bots (Improved A.I.), answered

Generated from the mod’s own source data.

Is it free?

Yes. Left 4 Bots (Improved A.I.) is free to download from Steam Workshop.

How do I add it to my Nxeon server?

Use “Add to a server” on this page, or open NxLabs from your dashboard. We install it, restart your server and switch it on.

NxLabs

Run Left 4 Bots (Improved A.I.) on a Left 4 Dead 2 server.

Free to download from Steam Workshop.