Mafia: Definitive Edition

JustAddMP/MafiaDE

A ground-up remake of the 2002 classic. In 1930s Lost Heaven, cab driver Tommy Angelo is pulled into the Salieri crime family and rises through the ranks of the mob, until the life starts to catch up with him.

C++Steam invitesNo server needed

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Get Mafia: Definitive Edition on Steam

Progress

Where co-op is at

Progress

43 of 65 tasks done

66%

FoundationsDone
Second player9/17
Custom charactersDone
Shared campaign6/15
Menus & UI9/10
Release10/14

Last commit 21 October 2026

Foundations

Done

Done: Game Scripting Access
Done: Player Movement
Done: Car Sync
Done: Docs & Screenshots

Second player

9/17

Done: Visible Drivers
Done: Passengers
Done: Shared Cars
Done: Combat Actions & Health
Done: Instant Player Spawn
Done: Main Menu Fix
Done: Damage & Respawns
Done: Character Models
To do: Animation SyncTested on two PCs: walking stays within about 1 m; rebuilt to stay within 0.8 m and match walk/run/sprint, plus fixes for swimming and changing character, waiting for a two-PC test
To do: Car Controls SyncTested on two PCs: copies drove too slowly and both players could take the wheel; rebuilt to stay within 1 m with skids and braking followed, waiting for a two-PC test
To do: Punches & Other Actions on PlayersTested: punches reach the other game and hit; the fix for them not showing is written, waiting for a test
To do: Staying in Car SeatsTested: drivers and passengers stay seated through long drives; the fix for a friend in his own mission car is written, waiting for a test
Done: Car Lights & Signals
To do: Jumps, Climbs & Carrying on PlayersBuilt in 0.15.0; only jumps seen in the first test
To do: MotorbikesRiders weren't visible in the two-PC test; written, waiting for a test
To do: Shooting Each OtherBullets didn't hurt the other player in the two-PC test; fix written, waiting for a test
To do: Three or Four PlayersBuilt in 0.15.0, waiting for a test

Custom characters

Done

Done: Model & Outfit Research
Done: Character List
Done: Character Picker
Done: Character Sync
Done: Safe Fallbacks

Shared campaign

6/15

Done: Weather & Time Sync
Done: Mission Sync
Done: NPC Sync
To do: Traffic SyncIn 0.17.0 the host's game runs all the traffic and friends see copies of it; checked on one PC, waiting for a two-PC test
To do: Pedestrian SyncIn 0.17.0 the host's game runs the people on the street and friends see copies of them; checked on one PC, waiting for a two-PC test
To do: Stay Near the HostIn 0.17.0: a warning past 300 m, and past 400 m a 10-second countdown before you're brought back beside the host; checked on one PC, waiting for a two-PC test
To do: Mission Car ReturnPartly tested: the swap works, parking it back not tested yet
To do: Enemies From a Friend's GameBuilt, waiting for a test
Done: Failed Missions in One Load
To do: Shared DoorsBuilt in 0.15.0, waiting for a test
To do: Shared Weapons & PickupsBuilt in 0.15.0, waiting for a test in a story fight
To do: Explosions on Every ScreenBuilt in 0.15.0: the messages and a grenade's flight arrive, the explosion itself not yet seen on screen
To do: Car Damage SyncBuilt in 0.15.0: dents and a blown-up car reached the other game; fixes for the repair mix-up and for matching car looks are written, waiting for a test
Done: Cutscene Sync
Done: Bandwidth Optimisation

Menus & UI

9/10

Done: CO-OP Menu Options
Done: Join & Leave Banners
Done: Hide Debug Text
Done: Gamepad & Mouse Support
Done: Steam Invites Between Two PCs
Done: Live Menu Updates
Done: Name Tags & Map Markers
Done: Settings Page
Done: Pre-game Lobby
To do: Every Player on the MapTested: markers follow each player in the logs; the fix for the missing minimap marker is written, waiting for a test

Release

10/14

Done: Version Matching
Done: Zip Download
Done: Public Pre-release v0.8.0
Done: Public Pre-release v0.9.0
Done: Public Pre-release v0.9.1
Done: Public Pre-release v0.10.0
Done: Public Pre-release v0.11.0
Done: Public Pre-release v0.12.0
Done: Public Pre-release v0.13.0
Done: Public Pre-release v0.14.0
To do: Public Pre-release v0.15.0Tested on two PCs; its fixes went into 0.16.0
To do: Public Pre-release v0.16.0Tested on two PCs: a friend on a motorbike couldn't be seen; fixed in 0.17.0
To do: Public Pre-release v0.17.0The host's game runs the whole world, with a zip of logs for every session; a Free Ride host who died could have their story save written over, fixed in 0.17.1
To do: Public Pre-release v0.17.1Out now as a pre-release: fixes 0.17.0's story save bug, the motorbike flicker, the missing CO-OP menu entry and characters stuck in cars; checked on one PC, waiting for a two-PC test

What works today

Play together, today

One small DLL, no separate server
Host and join from the game's own menus
Invite friends through Steam, or join by IP
See each other walk, run, draw weapons and drive
Pick your character and outfit in the co-op menu: Tommy, Paulie, Sam, Salieri and more of the story cast
Shots, punches and car hits hurt the other player; downed guests respawn next to the host
Drop into a host's game mid-session
A co-op lobby: everyone picks a character, readies up, and the host starts Free Ride, the story or any chapter for all at once
Play the story together: friends join the host at his checkpoint, see his objectives and watch his cutscenes
Your own saves stay untouched while you play in a friend's game
Names over the other players (hidden behind walls) and their markers on your minimap
Leaving is instant: when the host quits, everyone is told straight away; a crashed or killed game is noticed within about 4.5 seconds
Players stay where they really are on each other's screens: about 0.3 m apart on foot and 0.1 m in a car at speed (they could trail by several metres before), with live traffic numbers on the debug overlay
The host's enemies fight every player, not just the host, and the host sits at the wheel of mission cars on your screen
Shootouts are shared: a friend's kills count on the host's game too, so a friend can clear a fight on his own, and enemies match up again after a reload
Enemies only the host's game brought into a fight show up for friends too, moving and firing with the host's, and can be killed by either player
The co-op menus work with a gamepad and the mouse as well as the keyboard
The other player's car lights, indicators, horn, siren and police beacon show on your screen
A failed mission takes you back to the co-op checkpoint in one loading screen, at the right spot and with the mission's checks active, never into your own story save
Download the 0.17.1 pre-release zip and play; starting the game from Steam works too, if you want it

Not synced yet

These still run separately on each player's game. They're on the roadmap.

Player cars' colours

How to play

Up and running in minutes

1Download MafiaCoop-0.17.1.zip from Downloads, extract it anywhere and run MafiaCoop.exe. It starts the game with co-op built in.
2Host from CO-OP → Host Co-op Game in the main menu: the co-op lobby opens.
3Friends accept your Steam invite, or join by IP, pick a character and press Ready.
4The host picks Free Ride, Story or a chapter and presses Start: everyone loads in together.

Requirements

Windows 10 or 11, 64-bit
Mafia: Definitive Edition on Steam (the current build, 16502642)
Steam running and signed in

Known issues

Punches don't work near Salieri's bar, where Free Ride starts, or at some story checkpoints: the game itself turns fists off there
Your own new character shows once you close the pause menu (the others see it straight away)
0.17.1 was checked on one PC with two copies of the game, not yet on two PCs. After you play, each player sends the newest zip in the logs\bundles folder
Everyone needs 0.17.1 to connect; it can't play with 0.17.0. If you hosted Free Ride on 0.17.0 and died, check your story progress: 0.17.0 could write over your story save
Friends see the host's traffic, passers-by and police, not their own game's; going more than 400 m from the host brings you back beside the host after a 10-second countdown
Traffic far from you can sit up to about 2 m off to the side of where it is in the host's game
When the game keeps throwing a motorbike rider's character off the bike, the other screen shows it held on the saddle
A player's character in a front seat or at the wheel is now and then thrown out of the car on the other screen, more often on a slow connection
After a rejoin the lobby shows READY instead of JOIN GAME for a few seconds
A player sitting in a car can't be shot by the others, not even through an open window
After a player gets off a motorbike, its copy may stay on the other screens for up to a second
Fights were tested in one chapter's shootout only (Bon Appetit's restaurant, cleared, but the chapter wasn't played past it); traffic and passers-by come from the host's game since 0.17.0, not tested on two PCs yet
Enemies only a friend's game spawned, shared doors and items, and three or four players are built but not yet tested
Mission cars were checked in Taxi and Bon Appetit (the host at the wheel on your screen); the car coming back after the driver parks isn't tested yet
The co-op menus were tested with a virtual gamepad, not a physical one
Story co-op has been tested in a few chapters only (Omerta, Taxi, Bon Appetit and a few chapter starts)
A failed mission in a co-op chapter goes back to the checkpoint in one load; a blown-up mission car was tested, a mission timer and both players failing at once weren't
If a connection drops, the game reconnects on its own for up to a minute (worked on one PC; not yet tested over Steam between two PCs)