Synergy is a simple Half-Life 2 Modification (Mod) that enables you to play through the Half-Life 2 series and many other 3rd-party campaigns cooperatively with friends.
User reviews:
Recent:
Very Positive (75 reviews) - 90% of the 75 user reviews in the last 30 days are positive.
Overall:
Very Positive (3,104 reviews) - 94% of the 3,104 user reviews for this game are positive.
Release Date: Sep 1, 2005

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Community-Made Mod

This game requires that you own Half-Life 2.

Click here to learn more about mods on Steam.

Install Synergy

Half-Life 2 Mod

 

About This Game

Synergy is a simple Half-Life 2 Modification (Mod) that enables you to play through the Half-Life 2 series and many other 3rd-party campaigns cooperatively with friends.

Supported Games:

System Requirements

Windows
Mac OS X
SteamOS + Linux
    Minimum
    OS: Windows® 7 (32/64-bit)/Vista/XP
    Processor: 1.7 GHz Processor (Requires support for SSE2)
    Memory: 512MB RAM
    DirectX: DirectX® 8.1
    Hard Drive: 1 GB available space
    Sound Card: DirectX Compatible
    Network: Broadband Internet connection
    Recommended
    OS: Windows® 7 (32/64-bit)/Vista/XP
    Processor:Pentium 4 processor (3.0GHz, or better) (Requires support for SSE2)
    Memory: 1GB RAM
    DirectX: DirectX® 9
    Minimum
    OS: OS X Mountain Lion 10.8
    Processor: 1.7 GHz Processor
    Memory: 1GB RAM
    Graphics: NVIDIA GeForce 8 or higher, ATI X1600 or higher, or Intel HD 3000 or higher
    Hard Drive: 1 GB available space
    Network: Broadband Internet connection
    Minimum
    OS: Ubuntu 12.04, SteamOS
    Processor: 1.7 GHz Processor
    Memory: 1GB RAM
    Graphic Card: NVIDIA GeForce 8 or higher, ATI X1600 or higher, or Intel HD 3000 or higher
    Hard Drive: 1 GB available space
    Sound Card: OpenAL Compatible Sound Card
    Network: Broadband Internet connection
Customer reviews
Customer Review system updated! Learn more
Recent:
Very Positive (75 reviews)
Overall:
Very Positive (3,104 reviews)
Recently Posted
Chaser #TeamViking
48.8 hrs on record
Posted: August 24
Half-Life 2 with co-op?
♥♥♥♥ yes.
Helpful? Yes No Funny
Mario is not amused
2.1 hrs on record
Posted: August 24
Its good and all but very few people play it now
Helpful? Yes No Funny
Zarail
18.7 hrs on record
Posted: August 23
>Be me, who was back then part of a dying GMod community and some of us decided to play a game of this to remember the good times.
>We start of as four, looking for servers with only four slots because we don't want anyone else to join, and we're too lazy to host.
>We then join a 10 slot server and invite some more fellow community members.
>It's a cluster♥♥♥♥ as everyone else joins and starts screaming in mic chat. We all just ♥♥♥♥ around constantly, because who needs Freeman when you got 10 idiots running around, right?
>The server has an addon that adds an extra melee weapon; a pipe.
>Everyone starts swinging around with their new pipe weapons and start yelling "PIPE SQUAD" while making memes.
>I've never seen such a community work together so well in this game. It made me tear up before I had to go.

9/10 needs more pipes. And I need to check my ears.
Helpful? Yes No Funny
Masterpie [vacation]
15.9 hrs on record
Posted: August 22
First Level with a frien, cops beating us up we made a fort with boxes and briefcases in middle of leaving line thing cop corners me into a fence, proceeds to beat me up then sends my friend fliying 11/10 would build fort again.
Helpful? Yes No Funny
paekass
12.7 hrs on record
Posted: August 22
This game offers too many enemies for two people to handle
Helpful? Yes No Funny
Lean Shoe (PURUGLY BITCH)
2.5 hrs on record
Posted: August 20
Truly Stunning! Make sure you have a friend for this one.
Helpful? Yes No Funny
The Classic
53.9 hrs on record
Posted: August 20
GOODNESS GRACIOS! EVRY FREAKIN SERVER I GO ON PEOPLE CUSS AT ME AT TELLING ME TO GET OUT PLESE BAN THESE ANUSES
Helpful? Yes No Funny
oasis
26.7 hrs on record
Posted: August 19
♥♥♥♥ing fun download this ♥♥♥♥ now
Helpful? Yes No Funny
MarcusBesso
22.3 hrs on record
Posted: August 18
If you liked half-life 2, but wished that you could have played the maps co-op, then this is the mod for you. It's Free, and fun. Especially the servers that have mods like ROCKET LAUNCHERS FOR EVERYONE!

*Team of rocket launching wielding maniacs proceeds to blast their way through everything on a level in less than 2 minutes. Themselves included. :P
Helpful? Yes No Funny
Metapod
5.5 hrs on record
Posted: August 18
Got stuck inside my friend in the pod. Broke all the fonts on the intro to Ep.1 Got stuck in an infinite death cycle on the elevator that also caused my friend to get stuck in a loop. Died 400 times. Friend changed game speed to 9,000,000. Timed out from server. Friend got completely trapped in his own server. Spammed Windows + E. Opened 800 File Explorers. Friend's GPU hit 200 degrees. Friend got mentally scarred for life and is now terrified of all Source Engine games.

10/10 Would break HL2 and utterly f*** up everything in the game again.
Helpful? Yes No Funny
Most Helpful Reviews  In the past 30 days
6 of 7 people (86%) found this review helpful
6 people found this review funny
Recommended
2.4 hrs on record
Posted: August 7
This is a pedophiles hell, just wait on a server and call it "Free candy".
He won't recieve 10 year old minecraft chodelicker, but some crazy russians and germans screaming down the mic some weird stuff like "CYYYYKA".
10/10 Child lifeline and savior right here.
Was this review helpful? Yes No Funny
2 of 2 people (100%) found this review helpful
2 people found this review funny
Recommended
5.5 hrs on record
Posted: August 18
Got stuck inside my friend in the pod. Broke all the fonts on the intro to Ep.1 Got stuck in an infinite death cycle on the elevator that also caused my friend to get stuck in a loop. Died 400 times. Friend changed game speed to 9,000,000. Timed out from server. Friend got completely trapped in his own server. Spammed Windows + E. Opened 800 File Explorers. Friend's GPU hit 200 degrees. Friend got mentally scarred for life and is now terrified of all Source Engine games.

10/10 Would break HL2 and utterly f*** up everything in the game again.
Was this review helpful? Yes No Funny
1 of 2 people (50%) found this review helpful
1 person found this review funny
Recommended
27.5 hrs on record
Posted: July 24
What else can be said, it's HL2 with Co-op.

+all your favorite cancer clientside mods work too
Was this review helpful? Yes No Funny
Most Helpful Reviews  Overall
213 of 222 people (96%) found this review helpful
244 people found this review funny
Recommended
18.9 hrs on record
Posted: March 31, 2015
Pick up that can: Now with friends
Was this review helpful? Yes No Funny
223 of 235 people (95%) found this review helpful
Recommended
31.1 hrs on record
Posted: November 25, 2013
The best and only true Co-op mod for Half-Life 2's. It is little bit buggy, but aside of that having friend next to you bugs dosen't really matter. You are more likely to laugh to them than raging over them. I highly recommend this to people who are reaching together with friend for fun co-op experience that is of course Synergy.
Was this review helpful? Yes No Funny
148 of 152 people (97%) found this review helpful
51 people found this review funny
Recommended
127.3 hrs on record
Posted: November 10, 2014
Play HL2 maps with your friends. It's like HL2 except multiplayer. It's like GMOD except without the 10 minute loading times
Was this review helpful? Yes No Funny
137 of 139 people (99%) found this review helpful
159 people found this review funny
Recommended
12.0 hrs on record
Posted: January 2, 2015
When 15 of the one and only Gordan Freeman run into a hallway and simultaneously get whacked unconcious by the same cop, you know it's gonna be a good game. You start your journey by cooperatively breaking the mini teleporter in Kleiner's lab faster than a 10 year old on xbox live can realize when his internet has just cut out. Proceed to race your fellow chums to numerous respawning copies of the same laser mounted airboat before you have to wait in line with nothing but the sound your crowbar makes when it hits other players to entertain yourself. Stomp all over that antlion awaking sand because you brought an army this time and no one gives a ♥♥♥♥ about whether or not that rebel loser's friend is gonna get killed due to your lack of self reserve. Get vaporized at least 50 times in the combine elevators from violent swarms of electric balls launched by your cackling comrades. Lastly, break the shock and awe that resides in the silence of the game's final, time stopping, life endangering, jaw dropping, moments with a subtle "sometimes I dream about cheese" sounded off by using your keen dialogue wheel. 99/10, A player took out a whole server with an explosive barrel and followed it up by singing the national anthem.
Was this review helpful? Yes No Funny
136 of 144 people (94%) found this review helpful
142 people found this review funny
Recommended
39.3 hrs on record
Posted: November 28, 2015
Would be good if you had friends
Was this review helpful? Yes No Funny
96 of 99 people (97%) found this review helpful
28 people found this review funny
Recommended
8.6 hrs on record
Posted: November 15, 2014
Its like HL2 but without the "alone" feeling
Was this review helpful? Yes No Funny
104 of 113 people (92%) found this review helpful
1 person found this review funny
Recommended
53.1 hrs on record
Posted: April 17, 2014
I laughed, and cried. But I mostly laughed.

Want to play Half Life 2 with friends? here you go.
Was this review helpful? Yes No Funny