Running two wads with two dehacked lumps

Let's assume that I make a Boom Compatible Doom episode that take takes up MAP01-MAP05 and has its own dehacked lump. Then I make a wad that takes up MAP06-MAP11 and has a different dehacked lump, is there a way I could make it possible that you can run both wads together and not have one dehacked lump override the other?

If they both change the same thing, no.

Only option to make them one single mod would be to redesign both from the ground up so that they can use a shared deh lump. Depending on what they do, this might even require forsaking Boom-compat and using advanced content definition (DDF, DECORATE, EDF, etc.) instead of deh.

Extract a DEHACKED lump, remove it from the WAD, and load it as a BEX file along with the two wads.

DEHACKED lumps are parsed additively in MBF, but like others have said, if they both modify the same things, changes made by the latter may override changes made by the former, and the patches may conflict.

MBF (and EE) processes DEHACKED lumps in order from the oldest to the newest. So for example if you have done

eternity -file a.wad b.wad

DEHACKED in a.wad is processed first, followed by the DEHACKED in b.wad.

Please also note that DEHACKED lumps are *not* strictly a "Boom compatible" feature - they are in fact a feature of MBF compatibility. Since PrBoom imported most changes from MBF, this line was quickly blurred, however.

Quasar said:

DEHACKED lumps are parsed additively in MBF, but like others have said, if they both modify the same things, changes made by the latter may override changes made by the former, and the patches may conflict.

That's not the only issue here. Suppose that MAP01 to MAP05 use the imp a lot (for example), and it's supposed to be a normal imp. Then MAP06 to to MAP11 use a different enemy that is made from the imp with the second deh patch, and is noticeably different. When merging, there's no conflict because the first patch does not touch the content modified by the second patch; but it's nonetheless still an incompatibility...

Ususally, if properties overlap, the second one to be loaded up will change whatever it will change. Everything else it leaves alone.

The only port that I am aware of that can do this is Legacy. Las Rojas made Arctic-SE. Here is a copy/paste from his readme ...

For best results, this scenario should be played with
DOOM Legacy <http://legacy.newdoom.com/>. Mac users should
use Mac Legacy <http://doomlegacy.idevgames.com/>.

To play the first 11 levels (MAP09-MAP19), you must load the
following via Legacy's launcher:

ARCTIC.WAD
ARCTLEV.WAD
ARCTGFX1.WAD
ARCTIC1.DEH

Warp to MAP09 and start playing. When you reach the beginning
of the 12th level (MAP20, "Shark Farm"), save your game and
quit. Launch Legacy again and load the following:

ARCTIC.WAD
ARCTLEV.WAD
ARCTGFX2.WAD
ARCTIC2.DEH

Load your saved game and continue playing.

@hawkwind:
Nope. Those instructions involve the player saving their game after they reach a certain map, quitting Doom, manually reloading it with the other deh and resource wad, and loading their saved game to play the remaining levels. It was the same way for the vanilla version of Arctic Wolf.

I remember Quasar once talking about allowing making level specific changes to mobjs with EDF. I dunno if he ever got around to doing it though.

kristus said:

I remember Quasar once talking about allowing making level specific changes to mobjs with EDF. I dunno if he ever got around to doing it though.

A simple thing remapping feature should be easy to implement (perhaps via MAPINFO), e.g. 'remap_thing 9 3001'