The mod allows Doom 1 to be played as one level with no loading screens while connecting all the levels, the mod also allows Doom 2 to be played as one level with no loading screens. The main game keeps all the secret's, the weapon locations, etc....

The game itself is an on-going project that I'm doing by myself, this is being done for fun, so I can make the original Doom games seem like open world games.

This works best with Zandroum or ZDoom and not recommended with Zdaemon due to their strict rules that forces it to only work offline. It currently is working via Zandronum online, If I do post any multiplayer servers for any new/old builds then I will mention it on this page linked. (Usually hosted on Doom-seeker server under the name "Ultimate Doom Open World", is usually hosted by 'bestever' servers)

It's also been tested to work with the Doomsday engine.
>Due to legal reason's anyone downloading MUST have a copy of the
original Doom game's so please respect 'Id software' and buy a copy from
Steam or buy it even from their official website before downloading the
mod. (Requires the original Doom files to work)

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This is 3/4 of the map. Doom 2 Build 3 50% MappingOfDoom1as1level
Blog RSS Feed Post news Report abuse Latest News: Open World Doom mod adding all Ultimate Doom levels as 1 single level

5 comments by Ronnie42 on Feb 8th, 2014

Update 25/6/2015
Experimenting with porting Doom 1 to the Doom 2 engine but current texture issues are missing so will be looking into this. If works then it means being able to use the double barrel shot-gun on Doom 1.

Update: 15/9/2014

The Ultimate Doom 1 Beta 3 build has been tested, is now working on the Doomsday Engine.

Blog from Feb:

Currently I'm proud to say that the Ultimate Doom is now working as 1 single level. So you should in theory be able to explore the entire Ultimate Doom, be able to go anywhere, that includes all the secret levels (except the Xbox version's because I don't have those files)

Feel free to check the full preview here:

Doom 1 build here:

Doom 1 under 1 level.Version 3

(Doom 2 build can be found in downloads section but I'm trying to work on a new build, just currently have problems with loading more than 22 levels with the non-existent demon kill bug)
Downloads RSS Feed Upload file Latest Downloads
Doom 1 under 1 level.Version 3

Doom 1 under 1 level.Version 3

Feb 8, 2014 Full Version 9 comments

Open World Doom mod adding all Ultimate Doom levels as 1 single level.

Doom 1 as 1 level. Version 2.0

Doom 1 as 1 level. Version 2.0

Jan 4, 2014 Demo 0 comments

This is another build to try and get rid of bugs.

1st Attempt at fusing Doom1,2 together

1st Attempt at fusing Doom1,2 together

Dec 30, 2013 Demo 0 comments

Basically this is Doom 1's episode 2/3/4 fused while adding the first 2 levels of Doom 2 to make one continuous level.

BETA: Doom 2 compiled as one continuous level.

BETA: Doom 2 compiled as one continuous level.

Nov 21, 2013 Full Version 1 comment

Doom 2. All Doom 2 episodes under one continuous level with no loading screens.

Doom 2 episode 1 compiled.

Doom 2 episode 1 compiled.

Nov 21, 2013 Demo 2 comments

Basically the first 6 levels fused together as 1 level.

Full Doom 1 on 1 level with plenty of bugs

Full Doom 1 on 1 level with plenty of bugs

Nov 20, 2013 Full Version 5 comments

Basically this is for test purposes, if I somehow find a more stable build then I'll remove this then replace the download. This is not stable on the...

Post comment Comments  (0 - 10 of 17)
Randomguy7 Apr 26 2014, 7:45pm says:

The doom 1 open world version works. the doom 2 one starts at the end of the game and you can walk through the walls. the doom 1 and 2 version starts at some random map and there are broken textures. Still, excellent work!

+1 vote     reply to comment
Ronnie42 Creator
Ronnie42 Apr 28 2014, 7:59pm replied:

I'm still looking into the Doom 2 issue, seeing about rebuilding and fixing the wall issue but there's a lot more issues with the build.

I'm not sure which Doom 1 build you're referring to since the Doom 1 build version 3 always spawns near the start of Doom 1 for me.

+1 vote   reply to comment
mrdoom4you Mar 12 2014, 10:00pm says:

this looks so awesome

+2 votes     reply to comment
Ronnie42 Creator
Ronnie42 May 10 2014, 10:41am replied:

Thanks, also thanks for the rating too. :)

+1 vote   reply to comment
gamehacker Feb 9 2014, 7:19am says:

I'm liking it :)

It's funny that we've had the same sort of idea
If you look at the earlier test versions of e1m5 and e1m6 you'll see a example version of the Rage concept for my next project :)

The only difference is at the end of every level when you pull the switch a door opens to let the player outside to run to the next level :)

+2 votes     reply to comment
Ronnie42 Creator
Ronnie42 Feb 9 2014, 8:42am replied:

I was considering something like this but I was just trying to avoid too much programming to avoid any stress on the engine plus sometimes code would break so had to find work-around's to make it playable/fun.

+1 vote   reply to comment
Eonfge Dec 31 2013, 5:53am says:

You got a lot of work ahead of you. Let me give you a quick list of bullet points on stuff you will have to address:

* File format; consider using ZDoom format in UDMF, which is the most advanced format to support such large maps.
* Nod Builder; Check the kind of node-builder you use. Not all node builders will work with your map size so check ZDBSP/ZenNode out. Forget REJECT tables, with a map like yours that would be idiotic.
* Use ZDoom stable/GLZdoom Stable as development base. Zandronum is cool but not completely compatible and lacking some features which you will likely require.
* Use custom ACS scripts to simulate 'special events' like killing the Spider Mastermind.
* Use MAPINFO details and such to make sure people don't cheat using Zdoom features in a megawad that does not support them (no jumping for example)
* Check your voodoo dolls. At the moment, there are 30+ player 1 starting positions.

There are all just technical elements, but keep the artistic and gameplay part in mind:

* make smart use of teleporters to link maps together, don't just staple some hallways next to each other as it often breaks the level and art style.
* Make use of a starting-are with teleporters, which unlock once players reach certain areas in the map. As right now, if a player dies in E4, in multiplayer, he has to backtrack the entire first three episodes.
* Combining assets from Doom 1 into Doom 2 is technically a violation of the EULA and as such a copyright infringement. Fear not, there are already stand-alone packages with all Doom 1 and Doom 2 art, which you can take as dependencies. You could even use Doom 1 as a dependency, if players own both versions (who doesn't?).

These are the first things that come to my mind when looking at your project for 5 minutes. Good luck with it and I encourage you to get to know ZDoom and it's technologies, as they will be essential for you.

+4 votes     reply to comment
Ronnie42 Creator
Ronnie42 Dec 31 2013, 11:27am replied:

Sure I'll look into those since it sounds helpful.

I know we want to keep the teleports as they once were but the thing is they do break like a lot of things, there really one of many issues, I'm trying to fix like 'invisible' walls errors, I have noticed the teleporter's sometimes don't spawn in the right places so I'll either try fixing some or disabling some of them.

Also I'm aware of what might be against their EULA and have already messaged them previously, they actually liked what I was doing.

As for the dependency I'm mainly using Doom 2 for that so I can use things like the 'double barrel shotgun' in Doom 2.
Also I'll have a look at Zdoom at some point and curious about 'UDMF'. Also I understand 'special events' but trying to avoid changing those settings until I have a better understanding of ACS scripting.

+1 vote   reply to comment
Eonfge Dec 31 2013, 11:54am replied:

You have to keep in mind how the triggers in maps work. If there are two maps with a teleporter on tag 7, then the engine does not know for sure which sector 7 it has to refer too. Considering Doom and Doom II contain a few thousand unique tagged-lines with things like 'open door' or raise lift, you'll have to replace all of those.

The invisible walls are I think caused because you run out of computable space within one map. Same as for monsters that do nothing. Your map is so massive that stuff like REJECT tables (which trigger monster behaviour) and the BSP nodes get ****** up.

ACS will also be required for coloured keys. How else are you going to simulate 60+ keys in one map without them breaking sequences.

I previously looked into doing the same kind of project. No really! I too thought it would be interesting to have one continues playthrough of Doom but when I compared the costs (loads of scripting and technical limitations) compared to the gains (average load time of a Doom map), I decided not to do it.

Still, I think it's a very interesting learning scenario for you and I strongly encourage you to take some extra time to work things out. As a proof of concept, your Episode maps work fine but to do more, you should improve your skills and dare where no man has gone before.

+1 vote     reply to comment
Ronnie42 Creator
Ronnie42 Dec 31 2013, 12:42pm replied:

Yes I have noticed this issues but sometimes the issues become conflicting so I do try to trace the issues then try find fixes as I find them.

ACS? Will have to look into it, as for the computable space well I'll have to look into that too.

Also I have noticed an increased loading times which is why I'm considering just keeping separate builds but the fusion design was a prototype to see how far I can stretch the levels, I will will reattempt everything at a later time.

Also I understand I need to improve my skills, which is why mainly been doing this alone, I do it as a hobby/interest so will need to re-think everything before attempting any new build's.

+1 vote   reply to comment
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Doom 1 as 1 level, Doom 2 as 1 level
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Released Feb 9, 2014
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