It's not something you learn. It's more like something you just memorize and follow a pattern. The problem with EUD's is that they change every patch. They involve using the deaths condition to detect things in starcraft's memory, and the modify deaths action to affect starcraft's memory. However, EUD actions have been patched after 1.13, so if you want to use them, you have to downgrade. Here is a link to farty's EUD database.

Yeah unfortunately the search function is incomplete/bugged. It just stops after it found a few fitting posts.
But i looked through the old topics manually and found this. It's probably the most suitable thread for EUD beginners.

It has a lot of useful links, be sure to read them all, especially the tutorial on maplantis.
If after that you have still questions left just post them in your topic. There's usually someone around who can help you with tricky details.

Ah, thanks anyways guys. If they are disabled in the current patch, then I have no need for 'em

Thanks for your helps anyways.

You misunderstood. Eud actions have been disabled not conditions.

Yes, morphling is correct. Actions are disabled and you have to downgrade. But the conditions can still be very useful for some things, An example of this is Mouse Defense. It use's EUD's to detect the location of your cursor. Or Devilisk's Egg Ball. Which use's EUD's to detect which egg is selected and order a unit accordlingly. Actions may be disabled. But the conditions are still very much alive. If you play on making a map with them be carful. As previous people said patch's are constantly changing them and you would have to update your map.

The way EUDs work is by attempting to check deaths of units beyond the normal range, like players 1-255(256?), when you do this, rather than actually returning the proper death, StarCraft goes into memory later than the death table and grabs a value from there, so you can check different parts of memory through that.

A list of what some EUDs do can be found here, most 1.15.2 ones work with 1.15.3.

so how do you input EUD triggers?

StarForge I believe can enter them, and the latest versions of SCM Draft too.

thanks.
BTW this made a favorite post on my profile.

The latest version of scmdraft? Which version is that? I need it.

It's the latest news post I think you put UnitID: xxx or ID: xxx or something like that, I'd have to dig up the old topic..

Hm, I think the problem with EUDs is that people (like myself) get an idea that requires one or two EUD triggers, and then give up because it takes too long to figure out how to do what we want to do. What'd be really nice would be some sort of database of common triggers for EUDs, much more helpful than a bunch of numbers, even if the numbers theoretically can help you do anything. Something like "for unit HP detecting, you put the number of the unit on the map here, the HP you're looking for here, etc." Though doing this may be beyond the scope of somebody's time constraints, I really don't know.

The problem with that is you cannot detect a specific type of unit... you must detect a specific unit. If one knows what they are doing, it doesn't take much time at all to do an EUD trigger. Most the time (if it doesn't involve units) you just put the number in to EUDTrig and it gives you that information.

Well, my point was that the question of unit detection comes up quite often, and I'm sure it'd be easier just to say that trigger X finds unit 1's HP, trigger Y for unit 2, etc. than to go through EUDtrig, which takes quite a while to figure out.

My guide (now in 2 places, yay!) shows exactly how to find unit health, and there is a map to go along with it. It should probably go in the wiki (not my guide necessarily, but how to detect health).

@falkoner
I haven't needed to make an EUD map in a while, and I swear I can't figure out how to do it in SCMDraft. Every time I open up such a map, I get "invalid unit" instead of the unitID (in trigedit, classic shows it fine, and I haven't bothered editing it.)

Yeah, I'm pretty sure you have to use Classic Trigedit to do it.

I had to import them first, once they were there I could edit the death count and player, but not the unit number.

where do you put in the eud triggers?
is it in a window? how do you detect cursers? im at a loss here.

EUDs are just like any other detect deaths trigger. The only difference is you use a unit/player combo that forces SC to read past the death count data and into other memory(read: buffer overflow). You detect the location of the cursor by first finding out the memory address of the cursor's x position and y position. Then convert that address with EUDTrig, or manually if you know how. Its possible the address you use is not always accessible via EUDs.