for Half-Life

23rd June 2011

Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3

You find yourself on a spaceship, which seems to be researching Xen lifeforms.

Follow the clues to a spot on the ship and then ignore the sign.

At this point things turn fun!

Are you fast and smart enough to escape? Only time will tell….

This was May 2016’s Classic of the Month mod.

Basic Details
  • Title: Radix
  • File Name: hl1-sp-radix.7z
  • Original File Name: radix-steam.zip
  • Size : 10.07MB
  • Author: Unquenque
  • Date Released: 13 June 2002
  • Related: Project: Quantum Leap
Author’s Notes

This map was originally made for Project Quantum Leap – a cooperative project among forum regulars at the Valve Editing Resource Center.

I have released it as a standalone map partially because of the overwhelming positive response I’ve had to this map.

Download Options

Download to your HDD [10MB]

Installation Instructions
  • Copy the radix folder into your Half-Life folder.
  • Restart or start Steam.
  • Radix should now be listed in your Library tab.

If you require more help, please visit the Help page.


Radix is a HALL of FAME entry

Playthrough Videos

The playthrough below is part of the Classic of the Month Event, run by Don AKA Unq.


Click on the thumbnails below to open a 1024 pixel wide image.
WARNING: The screenshots contain spoilers.

Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3 Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
Reader Recommendations
Avoid It!
Think Twice
Play It Later
Play It Now!

26 recommendations, average score: 4.81 (out of 5), standard deviation: 0.16 (what's that?)
Total Downloads
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Meta Review Data
Statistics based on 14 comment(s) with meta review data.

Using Gauge: Users
Manually: 14 Users

Time Taken:
Average: 0 Hours, 30 Mins
Shortest: 0 Hours, 1 Mins by MisterYij
Longest: 1 Hours by DarkShift
Total Time Played: 6 Hours, 58 Mins
If you believe this release is missing important tags, please suggest them in a comment?
Special Events
Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3
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  1. Phillip's Favourite

    As my recommendation says WOW! This map oozes quality and design. From the moment you “portal” in to the moment you (hopefully) escape, you feel as though you are in a Valve-quality production. And I use the word production on purpose, because this map almost feels like a movie.

    The sound effects and use of stock voices from HL is perfect and as you have probably already seen the textures and design are fantastic.

    The gameplay is good, but not great, but that’s because I really know what I like.

    By far the best map added to the 100SDoN even so far and highly recommended.

    I won’t write any more until some other reviewers have posted their comments and then I am sure we can discuss a few things.

  2. Personal Favourite

    Haha, that was great right from the beginning. You dont see humor in half-life maps too often. And gotta love Bill 🙂

    That place really feels like space station (feels little like deathmatch maps called DM_Taragon and Squidsville).

    IMO good balance between Xen mobs and human Grunts.

    1. Remember to check Training Room too 🙂

  3. 2muchvideogames

    A while back I played project quantum leap, and this map was among it. Not only are the maps well designed and look great, there’s a healthy dose of humour as well. Not to mention, the spaceship setting is more refreshing than some generic warehouse/lab/office for sure. Gotta say, those handsome poke646 textures look good everywhere. When I played this for a period of time, I wondered, “wow, is this all really 1 map? There’s so much to do!” I don’t think I’ve ever seen a single independent map that has so much content and still be be enjoyable, but now I have. The alleged “overwhelming positive response” isn’t a joke. This map is really good. You have to try this. Preferably now.

  4. Play It Now!

    Heh, I remember playing this map together with all the other neat maps in the PQL mod. A really excellent map with tons of cool sequences and, an otherwise quite absent aspect in user maps, humor.

    Great and fair combat comes together with some really good-looking mapping. The author did a great job in making it feel very much like a space station with the custom textures and claustrophobic hallways and thus it does not feel like a Black Mesa in space.

    Criticism would be targeted towards some of the hallways very much looking the same, the very first fight with the alien grunts can be hard in that the player can easily miss the grenades near the crates and that it doesn’t explain any further on what happens to the headcrab character, Bill.
    These aren’t really huge issues on my part though and doesn’t affect the gameplay at all.

    1. Unq

      Ha! Great to see this map posted! I’ll refrain from rating it of course, but I do welcome criticism even after all these years.

      As for what happens to Bill in Radix…[spoiler]Take a close look at the first escape pod you run to![/spoiler]

      1. Haha, I just reloaded a previous save and saw it! Didn’t catch that the first time since I was so anxious to get off the station I didn’t notice him. Nice detail!

        Did you ever do a sequel with Bill as the main antagonist? I checked your site but didn’t notice anything regarding it. Mods and maps like this that doesn’t take itself all too serious is something I personally enjoy.

        1. Unq

          No sequel released yet. Although I’ve mulled ideas and mapped/coded/etc. quite a bit for other episodes. I can neither confirm nor deny they would be sequels starring Bill. Prequels, however?

  5. I feel like buying HL now… this is amazing!! :O

  6. Falconer

    The ending left me with the impression that there would be a sequel. Was one ever made?

  7. Play It Now!

    Very nice little mod. Great design, balance is nice, and the ending is great.

  8. Mel
    Play It Now!

    Having read most of posts for Radix here on PP, I don’t think I need to dwell on the merits of this mod, it’s set designs and textures are superb, imaginative and unique.

    What I was disappointed with was the shortness of the mod, and the fact that we were not treated to more sequences showing the author’s talent and mapping skills. Instead we had to be content with about three circuits of the same layout and surrounds.

    Without a doubt this is visually the finest mod so far this summer.

  9. Hec
    Personal Favourite

    This is a really good mod, I mean thecnically and in gameplay aspect, I think maybe would be the perfect sample of what should be a really good mod, not a really big I know is small, but with an especific goal and layout, also is fun and maybe there’s no big amount of combat but the battles are in the right place and really clever and just perfect suitted. So those are the reasons, because of i’m putting a Personal Favourite, which is unique here because I almost allways put a PF grade when I really like affectionally the mod, here is different because my bias are more on the tech and gameplay issues.

  10. Play It Now!

    I was really debating even leaving a review because I can’t think of anything that anyone hasn’t already said. But this was a great little map, the bill part made me chuckle a little and I was really hoping (fearing) that I’d see him again.

    I’m not sure I handled the first encounter correctly, but if I did, I think it was an interesting, albeit possibly flawed way to handle the first group of enemies. I only had a few grenades and I had to kill like 3 grunts with them. It wasn’t too difficult, but It definitely appears that you can run out of grenades and be left defenseless.

    1. Unq

      Yes that first combat encounter was kind of experimental. I specifically wanted to have something different than the old start with a crowbar and glock, etc. And I wanted the player to be shocked a little bit, especially if he/she just runs down the hallway without exploring a bit.

      There are 2 alien grunts only there, and 2 bundles of 5 grenades which should be plenty. In case of emergency, you can always run past and up the ladder.

  11. platoon

    nice and short,

    I played this with hard and its challenging, nice design, also texture’s make this mod very cool.
    I like the green neon texts idea very much, it makes areas like doom 3 and quake 4.

    i think bill need to replace with garg because its too big area for a headcrab its annoying it should be scary something you know, I laughed when I see it…

    i say it should be longer and it need to change the area a bit scarier , some sounds, bloods, flinking lights and dark…. but nice anyway…

  12. Play It Now!

    In this mod we will find ourselves in the top secret research spaceship. The ship is very stylish. Almost all textures are new.

    The mod opens with teleportation scene, which reminds of the game Space Quest 5.

    After all, our hero breaks the safety measures by unfreezing the cryogenic chamber which contained extremely dangerous intelligent monster. The bad consequences happen very soon. We fight monsters and soldiers. The encounters are quite original – fight back Alien Grunts with only the grenades, fight back soldiers and turrets and you have a Gauss Gun. The flow of the level is good – it’s hard to get lost even if you don’t put any effort into finding the way to progress.

    There is a small puzzle solving which will give access to the small secret area.

    Some criticism about the ending. Putting the headcrab in the first pod that player chooses to go is a great idea. But it is possible to not notice the headcrab before the door closes. What’s worse, the headcrab is non-solid and it’s possible to shoot it, which looks terrible and breaks the immersion. And if the doors are not closed, it’s possible to run to another pod and see that there are two headcrabs. I think that the cutscene would work much better here.

    The archive also contains another map, Rumble, which launches if you choose the training course. This map consists of spectacular and imaginative scripted event. Like in Radix, the dialogues that come with the game are used very well.

    1. Unq

      Valid and useful criticism on the finale, thank you. I didn’t know it was possible to see Bill and not have the door close, I assumed the player would be in more of a hurry. However, I am very much against cutscenes; I really believe Valve has the right approach to them.

  13. Play It Now!

    By far the best looking map so far with a balance of game play that I enjoyed. The thing that puzzled me however was waking up in the medical area after pressing the ” DO NOT PRESS” button, it seems to imply that someone took you there? Also this is one has a proper ending rather than just fade to black or back to menu as some of the previous maps have which gives the impression that thought and planning were part of build process.

    Overall a fun romp around a spaceship with combat that requires a thinking approach.

    More please Unq!!

  14. Play It Now!

    This is by far the best in the 100SDoN so far and with a very unique puzzle fight.

    As soon as I got to the first fight I knew that this was going to be a great mod, and I wasn’t disappointed. The textures were brilliant and gave a good feel or the spaceship type theme. The game play was pretty enjoyable and fights were well thought out. It also had an element of humor which was pretty nice too.

    The grenade fight against the Alien Grunts was fantastic and was the main reason I loved this mod. I have never seen anything like that in any HL mod and it was very unique indeed. The scripted lines of the Barney’s and scientists worked well and was humorous in many occasions. The massive safe which opens revealing a small Headcrab was pretty funny too. I was expecting Bill to be a Barney or something, probably because of the main screenshot.

    I guess it’s time to get to the flaws, but personally I can only think of two. First of all the Bill scene at the end happened too fast and was only possible to see him for about a second, meaning a lot of people would have probably missed him. The second was that it was way too short, and this is the only reason I have not given it a “Personal Favourite”.

    We need to have another one of these, whether it is extended from the original one or a follow up. Is there any potential extension/sequel?

    This was just brilliant and barely misses “Personal Favourite” for me. It’s a must play and the best so far.

  15. Play It Now!

    This was a very high quality mod and I enjoyed it immensely. I think what really made it for me were the visuals and the very well produced scripted sequences. I also thought the scripted sequence hidden as the training course was very entertaining as well. It’s a pity that that bit is sort of hidden because I think a lot of people will miss it.

    The environments are this time in a spaceship so areas look vastly different to what we usually see and, for me, it was quite refreshing. The layout and all the new textures made me feel like I was in a spaceship and it just felt like everything belonged there logically. In general, it was pretty hard to find fault with visuals. It just looked very well polished.

    I especially enjoyed the scripted sequences. I think it was mainly because I could recognise the stock lines but they were used in a completely different context. Though, the idea behind Bill was fantastic as well. I truly wasn’t expecting it.

    The combat, I felt, was what held it back a bit. The initial alien encounter was a nice change but the game-play moved back into the standard run and gun style. It wasn’t too bad overall but I felt that the combat towards the end with the grunts was starting to feel a bit repetitive, especially for such a small and relatively uninteresting area to play in. There also wasn’t much of an explanation of where the grunts came from either, which interrupted the immersion for me.

    On the whole, this is an excellent, well-rounded example of the quality that mappers should aspire to. I highly recommend playing this mod.

  16. Play It Later

    It’s a pity it’s that short, as I mostly can agree with the other comments here, meaning it’s very well designed altho not much detail imo

    The start was hard, killing a Grunt with.. oh! (Life drops to 90, 50, 5) There are hand grenades!!! Phew! O:) Walking back to the health stations hehe.. nice start!
    And it continues with nice combat against my fav enemy: soldiers!
    But where’s my shotgun ??? :(((

    -Neat leveldesign with many non-HL textures (but from mods!)
    -Quite good space atmosphere
    -Excellent balanced, except for the beginning maybe 😉
    -Nice combat action
    -“Rumble” as hazard course
    -Bill !

    -Unfortunately very short
    -Less weapons & enemy types (hum I can’t say I miss the Apache on a spaceship but… O:)
    -Maybe space isn’t everyone’s fav layout, like for me (altho I do play every good mod, no matter where it takes place, I also played & liked USS Darkstar for example..)

  17. Personal Favourite

    Rumble :-

    HAHAHA!!! This map is really hilarious :D. It has nice application of sounds with ole” Barking-Dog’s famous “Pop Dog” included here. I like the way… but oh… just download it and see it for yourself.

    You’ll have the laugh of a “half-lifetime” xD.

    Radix :-

    When it comes to single player single maps, there are not many maps that closely resemble quality. But same cannot be said of Radix. It is evident that the author has worked hard to make this map.

    The entire intro sequence is superb. I love ole Bill. :D. It’s a really ingenious idea by the author keeping Bill as the enemy. This is one of the most funny map that I have ever played.

    Mapping is really nice. We really feel as if we are in a spaceship. The new textures have been cleverly applied. The “larger” areas of the map like the alien study chamber should have been more larger. I mean it is supposed to be a space station which are really big and spacious. That is my only complaint here.

    Gameplay is really easy especially with the gauss gun provided. The first part of combat is difficult. People may not notice the grenades lying there in the corner before the run for cover there. After you kill the first Alien Grunt, rest of it is easy. We face two assassins in the end but one I blew up with a satchel charge and I emptied the entire Gauss ammo on the other >:D. The best part here is
    whichever exit route you choose, you meet Bill who closes the door quickly before you have a time to react. Then its 15 secs to dodge / kill the assassins and take the other route.

    Overall this map was fun to play and is one of my personal favorites :D.

  18. Play It Later

    This is a fun little short mod. The humour was great, but it’s a shame I didn’t get to use a shotgun or the MP5’s grenades, but it really does make you appreciate the pistol and the tau cannon.

    Give this mod a go when you have the time, but watch out for Bill!

  19. Play It Now!

    Short and sweet. I was expecting longer, but still satisfied. I love the use of the Half-Life voices to create humor, I’ve always loved that in HL maps and mods.
    Visually nice, good gameplay, humor. A good map overall.

  20. Short and Sweet little mod.

  21. Play It Now!

    This was a very enjoyable and high quality experience. I loved exploring the space ship and the comedy aspects are fantastic. Be sure to check out the training room!

  22. Personal Favourite

    Going in to this mod I expected it to be similar to Someplace Else why I had that impression? I have no idea. Even though I played the training room first I just assumed it was just a little joke thrown in. So I started up the map saw the clever use of the usual scientist voice files for humor, laughed and moved on again thinking nothing of it. Then I saw Bill and that is when I lost it. This map is great short, fun, funny, and just the right amount of challenging. It most definitely deserves its spot in the hall of fame.

  23. Was very disappointed with this Mod. Seen Unquenque play it on a RTSL live stream and wanted to record a Walkthrough for my channel.

    It does look amazing – difficult to believe it’s the GoldSrc engine when playing.

    However – there is a game breaking bug about 10 minutes into it – were Barney gets stuck on the lift. Tried it countless times on 3 different computers with different versions of HL – and same result.

    After around 50 attempts I gave up. This is the first Half-Life Mod I have ever encountered with a game breaking bug that can’t be worked around via the console.

    I’ve seen other people play it on YouTube without this bug, so it seems to be hit and miss – will work for some, won’t work for others. Might just be a waste of your time like mine.

    1. Unq

      Haha, ouch. Would you believe you’re the first person to have this bug that I know of? Damn.

      I specifically asked everyone who tested it back in the day if this happened, since it was around the time where the dreaded HL elevator bug was prevalent.

      You say you’ve tried different HL versions, I assume you’ve tried Steam, WON, and perhaps NGHL?

      You should be able to noclip through the locked Armory door to progress. Sorry is all I can say. 🙁

      1. Gordon also gets stuck many times, but that can be avoided with a well timed jump.

        Not only me that has this problem – https://www.youtube.com/watch?v=2mrw8GyUduE – notice his little jump too.

        I blame your Beta Testers 😉

  24. Play It Later

    Very short mod, it can be finished in 30 minutes! The textures are really nice, which set the ambient for the whole spaceship. It’s a bit joke-ish, but overall it is fun to play, with good choice of weapons too.

  25. Crashes

    1. Unq

      Rating removed since you didn’t actually play it. It crashes because of Valve’s update to HL last week.

      Opt in to the beta version of HL on Steam, or fix it yourself:

      open liblist.gam (text file) in the mod folder, and change:

      gamedll “..\valve\dlls\hl.dll”


      gamedll “dlls\hl.dll”

  26. Play It Now!

    A short, fun experience. Gordon, stop pressing things that explicitly says do not press.

    The mod can be a bit difficult for some, as you are pit against a lot of Marines with only the SMG and the Tau Canon. I also did not notice the grenades at the start, so I just tried running past them.

  27. Play It Now!

    Nice mod! I like the sense of humor in the game, and the space station design is very nice. There are not many combats but they are fun!

  28. Play It Later

    Bill is one savage headcrab ngl

  29. Personal Favourite

    RADIX is an amazing map. There’s fun combat, good comedy (I actually laughed out loud a couple times), and the most menacing villain in the Half-Life universe yet.

    I really liked all the small details, along with the new textures, and the layout actually made sense for a spaceship! (looking at you, Darkstar). I wish the mod was a bit longer, but at the same time, I feel like the short length allows it to really excel.

    Also, the added map, RUMBLE, is a nice bonus, with some very nice scripted sequences. You can access it through the training room.

    1. I didn’t expect to find another personal favorite so soon!

  30. Personal Favourite

    It ain’t much but honest work. Awesome mod I love everything about it: The style, humor, surrounding, lightning. A lot of effort author putted in. Great mod.

  31. Play It Now!

    Definition of short and sweet. Good level and combat design. Very nice and detailed mapping, love how the space ship looks. Quite charming to, love the sense of humor in this map. Basically Half Life but bit sized, and in space. Recommended!

  32. Play It Now!

    It looks like a joke mod with a headcrab being the antagonist.
    It is very impressively detailed, and the combat is balanced as well (maybe a bit too easy).

  33. Play It Later

    Only reason I gave it 4 stars is because it was way too short for my taste. Another half an hour of the experience would be enough, but this was just way too short.

    Textures and map design were nice, joke-ish feel of the mod, I must say, felt nicely refreshing comaperd to other things Half-Life community has brought us, so I consider it a plus. Gameplay was your average Half-Life gameplay, which is okay.

    Overall, good mod if you want something to play while waiting for something else to download or if you are just for a small treat of a game, but if you are for something more than that, go look somewhere else.

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