Changes made from DDP to GOTL/SOTG to ROTE.... to Disciples II Gold :

DISCIPLES II GOLD
Mostly for new players or a chance to get the whole series for the old players and available since February 2005, Disciples II Gold contains all the four games : Dark Prophecy, Guardians of the Light, Servants of the Dark and Rise of the Elves. You also get five new scenarios.

Danny K and Warchild from Strategy First Inc. provided these informations about the Disciples Series for the fans who asked for the changes from the original Dark Prophecy to Rise of the Elves. You can find more on SFI forum in the technical support section, look for the sticky. I added a few infos from the notes I took. And yes, for those who asked, I get all of them, even the original D1. No I did not play all the scenarios and sagas and no, I don't mind too much the changes. I prefer to use the original version most of the time because it was harder and some custom made scenario were made for a specific version making them too easy in a later version.

GAMES OF THE DISCIPLES SERIES
The Disciples 2 Expansions : Guardians of the Light, Servants of the Dark and Rise of the Elves are standalone.
Guardians of the Light allows you to play the full campaigns, seven original chapters and three high level chapters, of the two good races : Empire and Mountain Clan.

Servants of the Dark allows you to play the full campaigns, seven original chapters and three high level chapters, of the two evil races : Undead Horde and Legion of the Damned.
Gallean's Return includes both Guardians of the Light and Servants of the Dark.
You need level 10 leaders in order to play the expansions. If you don't have your own, you can find level 10 leaders on the first Disciples CD under D:\Bonus\Exported leaders.

Rise of the Elves allows you to play the original Dark Prophecy campaigns of all four races, except the high level campaigns from GOTL and SOTD, and introduces a new race, the Elves, with their own campaign, a seven chapters saga.

SCENARIOS OF THE DISCIPLES SERIES
Gallean's Return, GOTE, SOTD include all the original scenario plus the five extra scenarios that were in the Collector's Edition, and have quests unique to them that are not found in the original Disciples 2. Rise of the Elves includes new unique scenarios for the new race, the Elven Alliance.

The expansions allows to create larger map (144x144, but the limited stacks number is 200).

You can play the scenario for all races in all the games if you have the right minimum version, this goes all well for the custom scenario.

You get five new bonus scenarios in Disciples II Gold.

GENERAL INFOS :
Guardians of the Light and Servants of the Dark feature new story-based characters as well as four new bosses to end each campaign, and new units (Spirit Wolf and Lachla'an). New items related to the campaign.

Rise of the Elves includes the Elves as a playable race, two new bosses, four new units in a "mystery" race, two new Barbarians, and two new Greenskins. New items, new orbs and artifacts, grove mana and new spells for the Elven Alliance.

Maximum experience for the leaders had been increase to 18 in all the expansions (GOTD, SOTD, ROTE) and the maximum for a custom leader is 99. The damage for the leaders in the expansions campaigns is now 400.

Rise of the Elves features new abilities and damage types (critical hit, blister, shatter), a re-balancing of certain units, adjusting the strength of the mage leader and the Nosferat, by lowering their chance to hit, and a bonus to regeneration (10%) if standing on your own terrain.

Attacks and wards had been modified for a few units like blister for the Overlord and the Gargoyle is now immune to poison.