In "The Hidden", players choose the role of either a near invisible killer, Subject 617, or one member of an Intercept squad who have to capture him, I.R.I.S. In the simple but challenging gameplay of an 'one against all'? mode, Subject 617 creeps/sneaks through the maps armed only with a knife and three pipe bombs. The IRIS team carry a selection of weaponry, fully customisable at round start, from F2000 assault rifles through to shotguns or sub machine guns as well as a pistol as a secondary weapon.

However, they can hardly see Subject 617 as, just like the 'Predator', only the outline of his silhouette is visible. On top of that the Hidden also moves a little faster and has many abilites such as pouncing, wall grabbing, corpse pinning and the fatal pigsticker attack. Therefore co-operation is necessary for I.R.I.S. if they wish to prevail (if they dont want to become the prey/victim themselves).

This leads to an outstanding gaming experience on public servers: The I.R.I.S team creep/sneak through the corridors, back to back & covering each other whilst Subject 617 lurks in dark corners choosing his time to attack. The player who finally kills the Hidden takes over the role & from then on he can roam like a ghost through the corridors.


In the early 1950's human genetics experimentation was taking its first, tentative, steps. Amongst many other black projects, a team of British scientists working at a Infinitum Research experimental station stumbled across some remarkable phenomenon involving DNA manipulation. This led to deeper research with dangerously unpredictable results, often leading to human patients losing their lives in irresponsible and immoral experiments.

Time passed on, and by the mid 1990's the failure rate of the experiments had been reduced from 75% to a mere 15%, enough for Infinitum to move onto the next stage, Biological Light Refraction. The British team were hoping to unravel the possibilities of light manipulation to create the perfect covert military agent. Early into the new millennium, due to a gross miscalculation, a series of tests on Subject 617 led to a massive synaptic trauma leaving the patient with multiple genetic anomalies.

The subject was left in constant pain and with unstable DNA. The subject escaped captivity, killing anyone that got in its way, the I.R.I.S (Infinitum Research Intercept Squad) team have been deployed to return the subject to a maximum security Infinitum Research facility for further study and dissection. The entire project was considered a failure, all funding ceased and development was discontinued. All records and traces of the experiments were destroyed. Infinitum Research denies all knowledge of any form of human DNA manipulation but are more than happy to comment on the possibilities of cloning human organs inside suitable animal donors. It is believed that these organ cloning experiments form the main cover for their human genetic manipulation experimentation.

As the I.R.I.S team close their net around it, subject 617, known as The Hidden must turn the tables becoming the hunter instead of the hunted!

Vist the website

Image RSS Feed Screens
HEX Sigma HDR Shot 1 Equipment Selection Menu Concept Character Selection Menu Concept
RSS Feed Articles

While it's not Beta 5, we felt that enough's enough and that we had to get something out the door. So while this update does nothing on the code side of things (we didn't want to go back and try and jury-rig the old code base into a releaseable state - the additional problems that would create would be endless!) it does update the mods steamappid to 215 (we appreciate that a number of players and servers have already done this, but with this update everyone should be on the same playing field and we should have no more problems with one group being unable to play on certain servers!)

We've scrapped Manor (if you've been following the forum, you'll be aware of this) but rather than leave you with one less map, we've fixed up hdn_origin by removing the lag inducing shakes and replaced manor with the much more atmospheric and decidely sexy Decay.

Aside from those major changes, this update includes a number of alterations to materials and models and includes a whole new look and feel to the menus and front end! Though keep in mind, we have held back some art updates for Beta 5, just so we've got some new shinies to go along with the new gameplay mode and feature set.

NOTE: This update breaks compatibility between 4A clients and 4B servers (and vice versa) due to material alterations.

Personally, I think I have too much bloom. Maybe that's the trouble with me

Personally, I think I have too much bloom. Maybe that's the trouble with me

9 years ago News 1 comment

Ahha, a progress report! While I do not exactly bring the best of news, in that this is not going to give you a date for our next release, it should at...

Hidden Stats Launched

Hidden Stats Launched

9 years ago News 2 comments

Dear ModDB, My name is Robert "RaideR" Baxter-Kaneen, team leader of The team and I have been working on this service for about 4 weeks, and...

Hidden Source Beta 4 Released!

Hidden Source Beta 4 Released!

9 years ago News 7 comments

We said we were going to attempt monthly updates from here to the end, and we have 'near enough' done it this time, give or take a week. In our mad rush...

Hidden Source updates to Beta 4!

Hidden Source updates to Beta 4!

9 years ago News 0 comments

Falling just over the 4 week deadline we set ourselves at the release of Beta 3, it's here, the smaller but no less tasty, Beta 4! As you may appreciate...

In "The Hidden", players choose the role of either a near invisible killer, Subject 617, or one member of an Intercept squad who have to capture him, I.R.I.S. In the simple but challenging gameplay of an 'one against all'? mode, Subject 617 creeps/sneaks...
RSS Feed Downloads
Hidden : Source Beta 4b Server

Hidden : Source Beta 4b Server

8 years ago Full Version 48 comments

This is the complete installer for Hidden Source beta 4b dedicated servers - if you are already running a beta 4a server, you may wish to only download...

Hidden Source Beta 4b Server update

Hidden Source Beta 4b Server update

8 years ago Patch 3 comments

This is the update file for existing beta 4b dedicated servers, it does include new binary files as they remained unchanged. Please note, you should remove...

Hidden Source beta 4b Client Update

Hidden Source beta 4b Client Update

8 years ago Patch 67 comments

This is the client update for the Beta 4b release of Hidden Source, please only use this if you have an existing Beta 4a install you wish to update ...

Hidden Source Beta 4b

Hidden Source Beta 4b

8 years ago Full Version 515 comments

This is a full installer for Beta 4b of Hidden Source - it introduces a new map, hdn_decay and a number of graphical alterations. If you do not have an...

Hidden : Source Beta 4a Client Update

9 years ago Patch 4 comments

This is a Client only update to the recently released Beta 4 of , it fixes a number of small issues and make some gameplay tweaks for balancing. For more...

Hidden : Source Beta 4a Server Update

9 years ago Patch 1 comment

This is a Server only update to the recently released Beta 4 of , it fixes a number of small issues and make some gameplay tweaks for balancing. For more...

Post comment Comments  (70 - 80 of 542)
Auxor Aug 30 2012 says:

Uh... while I loved this mod, i'm curious to know why its suddenly become so popular on Moddb again.

+3 votes     reply to comment
PsychaanRiver Sep 6 2012 replied:

Famous Youtube gamers have been playing lately.

+5 votes     reply to comment
EricFong Sep 21 2012 replied:

The guys I know It's being playing it, Kilplix, Nanners and etc

+1 vote     reply to comment
Andrey(Rus) Aug 29 2012 says:

I thought there is an update to this awesome mod :(((

0 votes     reply to comment
Color-Copycat Aug 29 2012 says:

I don't know what you guys are talking about. In the afternoons, I get roughly 2-3 populated servers with decent matches going on.

+1 vote     reply to comment
psycho1997 Aug 22 2012 says:

does anyone know any ip to someserver cus i really want 2 play this mod

+1 vote     reply to comment
LOTEC[RUS] Aug 19 2012 says:

Why there aren't any servers? This mod is really awesome and fun to play. :(
I think the developers must go to Kickstarter and make they own independent project...

+3 votes     reply to comment
U-Jooy Aug 12 2012 says:

This ******* awesome mod needs servers again!
It's still in beta, but it's very well playable and not that much unknown.
So I don't know, why there aren't any servers.
It's kinda sad. :(

+1 vote     reply to comment
TotoKwok Aug 8 2012 says:

Grid View pic of Hidden Source for Steam!

(all credit goes to Ging)

+1 vote     reply to comment
Th3darkfunk Jul 30 2012 says:

I really want to play this with my friends, but i cant do anything without it giving me the "error verifying steam ticket".
I tried restarting it, deleting Steam.dll steamui.dll, logging out and in, and reinstalling but nothing is working :c

+1 vote     reply to comment
U-Jooy Aug 5 2012 replied:

I also had the same error with all mods. It just worked after I've reinstalled my hole computer.
You've got bad luck, I think :(

+1 vote     reply to comment
Dune_Jumper Jul 26 2012 says:

Everyone is saying this is still alive, yet I can't find any servers.
Like AT ALL. :(

+1 vote     reply to comment
iberaider Jul 27 2012 replied:

The servers are there. Development wise, the game is dead. But the beta is still played alot.

0 votes     reply to comment
Dune_Jumper Jul 28 2012 replied:

Then why AREN'T there any servers?

+1 vote     reply to comment
warthriller Aug 3 2012 replied:

probably a problem w/ your masterserverlist

+1 vote     reply to comment
Post a Comment
click to sign in

You are not logged in, your comment will be anonymous unless you join the community today (totally free - or sign in with your social account on the right) which we encourage all contributors to do.

2000 characters limit; HTML formatting and smileys are not supported - text only

Half-Life 2 Icon
Developed By
Send Message
Official Page
Release Date
Released 2007
Mod Watch
Track this mod
Community Rating



671 votes submitted.

You Say


Ratings closed.

Highest Rated (2 agree) 10/10

One the most fun Source mods out there, even in just a beta form.

Easily deserving a 10/10.

Tip for IRIS players: Hunt the Hidden, don't let him hunt you.

Fun thing for Hidden players: Get really good at playing as the Hidden, then play against about 3 noob IRIS players, and scare the hell outta them. :D

Jan 30 2011 by MattmanDude

First Person Shooter
Embed Buttons

Promote Hidden Source on your homepage or blog by selecting a button and using the embed code provided (more).

Hidden Source Hidden Source
Hidden Source
Last Update
11 months ago
1,248 members