I was reading that Ubisoft did a remake of it that really aside from polishing up the sprites there is no difference except buggier and more likely to crash.

I looked up the version here and both "New World Computing" and "Ubisoft" are listed.

Is the GOG version the old or new version?

The GOG version is the original version of the game and not Ubisoft's ill-conceived "HD remaster" (which, among other things, doesn't have either of the expansions.)

GoG release of HoMM3 is based on Heroes of Might and Magic III Complete Edition by New World Computing released September 2000. It contains main game (The Restoration of Erathia, RoE) with two expansion packs: Armageddon's Blade (AB) and Shadow of Death (SoD) standalone expansion. Unfortunately few contents from original Heroes of Might and Magic III: The Restoration of Erathia (released February 1999) were not included in Complete Edition, like high quality (Bink) Campaign videos. Original RoE campaigns are known to be broken when playing in SoD. Other campaigns and single scenarios are working well.

Ubisoft (HD) remake of HoMM III: RoE doesn't include expansion packs and random map generator. It is very unstable also so avoid it at any cost.

This is news to me. Which campaigns are broken, and in what way?

Ubisoft is the publisher and current IP owner (purchased some 3DO assets in the early 2000s after it closed due to financial problems and abysmal leadership). They didn't make the HD Edition (or any other game), DotEmu did.

TL;DR - get it on GOG, you get more for a considerably smaller price.

Thanks :) that's why I was asking to begin with, just to make sure

I replayed all original RoE campaigns (using DVD Complete Edition, not the GOG one), and none seemed broken. So I'm curious too.

Maybe you could send them your edition then, so they could upload it? That way we can have those RoE campaigns the way they should be played! :)

What is wrong with the GOG's version? Isn't it excactly same as the DVD one?

No, I'm surprised that you're asking me since Tarnum just told you above and you asked him about it as well. :D

"Original RoE campaigns are known to be broken when playing in SoD. "

We've actually talked with them about this before in a different thread, and several other people confirmed that in the GOG version the heroes don't carry over the way they should in the RoE campaigns, so you get random heroes and not the ones you were using that were supposed to carry over.

I did read Tarnum's comment, I was seconding Bookwyrm's question: "Which campaigns are broken, and in what way?"
Could you link me to the thread? I'd be happy to check my DVD, but I'd rather know the specifics.
If I remember correctly, there was only one case where it was broken for me. In the Tatalia/Krewlod campaign, if you choose your Tatalia heroes for level 3, then instead of having all 8 carry over, you only get 7 and 1 random one. Hardly an important glitch, since you only use 2-3 heroes at most and the rest are just backup.

However I played both the Millenium Edition (on CD) and Complete Edition (DVD) so I'm not 100% sure which one this happened in. If you give me more specifics, I could check.

What did happen in my DVD edition, is that heroes don't get carried over in Shadow of Death between campaigns. But I thought this was normal; you can only carry heroes between levels of a single campaign, but not between different campaigns. However, this had nothing to do with RoE.

Sure thing! :)

https://www.gog.com/forum/heroes_of_might_and_magic_series/homam_iii_there_is_no_patch_for_transfer_bugs

And here are two discussions about quest artifacts and heroes not carrying over when they should: (and oh hey! You actually participated in one of them!)

https://www.gog.com/forum/heroes_of_might_and_magic_series/homm_3_liberation_campaign_border_guard_quests

https://www.gog.com/forum/heroes_of_might_and_magic_series/heroes_3_shadow_of_death_carryover

Also in one of the replies in my thread someone says that the bugs were supposedly fixed in the 3+4 DVD complete edition, so it might've been that one where it worked for you.

This has nothing to do with Restoration of Erathia. It is the Shadow of Death campaign.
As I said, heroes carry over between missions in a single campaign, but not between campaigns. Because it looks like the the game had no mechanic to do so. As my edited post in that thread states, the same problem exists in my DVD version.

In this post Tarnum wrote (and this is what Bookwyrm asked about): So it can't be what he was referring to.

Well in one thread it is stated that heroes don't carry over in RoE as they should because SoD broke them.

In another thread (or two of them it's stated) that in SoD some things don't carry over as they should.

"It affects the Shadow of Death campaigns. The heroes stats\skills don't transfer from the 4 starter campaigns (featuring Gem, Yog, Gelu, Crag Hack) to the next one in the sequence (Unholy Alliance, iirc)."

So there are two different problems.

You're right it's two different problems.

No. It's a case of artifacts not carrying over in one campaign. Or rather, the carry over happens correctly, but the quest guard asks you for the wrong artifact. I investigated this and here is what I found:

Basically, in Liberation campaign, you can play levels in any of the two orders:

1,2,3,4
OR
1,3,2,4

If you get the quest artifacts, they carry over, and depending which of the above orders you choose, you should get a different artifact in level 4, which can be exchanged for a fairly powerful one.

Unfortunately, one of those paths is broken. The quest guard asks you for the incorrect one. Which means if you choose one of those paths, you will end up with no artifact in level 4. I have explained it in more detail in the thread.

I can confirm that this problem was introduced with Complete Edition (both DVD and GOG). I installed my old CD edition of HoMM 3 and both paths worked properly.

However, if this is what Tarnum meant by "RoE being broken" then I have to disagree with him. This is hardly a game breaking bug. You can still get the artifacts if you play the levels in the correct order (granted you have no way of knowing it, and if you choose the wrong order it would be annoying having to replay the levels in the correct order), and even if you don't, the only thing that will happen is that you won't have a powerful artifact in level 4. While an inconvenience, the level is perfectly finishable without it; those quest guards were optional in the first place). Finally, as someone noted, you can keep reloading till you get the artifacts you want from an Artifact Merchant.

Just a little clarification on this.
Campaign 1 features Gem. She does carry over between levels of this campaign.
Campaign 2 features Crag Hack. He does carry over between levels of this campaign.
... same thig for Yog and Gelu in campaigns 3 and 4.

Now campiagn 6 has all four heroes combined. Only instead of having them carried over from each previous campaign, they are not. Note that they are still high level and about as powerful as they'd have been had they carried over, only their secondary skill are probably different from what you want them to be.

I wouldn't say it's a bug per se. Heroes of Might and Magic 3 did not have a mechanic of carrying heroes over between campaigns, so it was impossible to do this. What they could have done is have all those levels in one single campaign, in which case carryover would work (though having it crammed in one campaign would look ugly).

Either way, this is Shadow of Death Campaign, so can't be "RoE being broken" that Tarnum wrote about.