The information presented in these archived FotDs is now outdated, but that's often the most interesting thing about them, seeing how much the game has changed from then to now.
The original FotDs are indented and italicized. Explanatory comments below them were written by Flux at the time the FotDs were archived, usually a couple/few months after the original FotDs had been presented.
December 6, 2000
- The last surface area of Act Two, the Canyon of the Magi, has the same layout every game, including the location of the seven tombs. Which tomb is the correct one, with the entrance to Tal Rasha's Tomb and Duriel inside varies, and you must defeat the Summoner to find the correct symbol, but the symbols are all in the same locations every time. You can see a screenshot with a cool mini-map of the fixed tomb locations right here.
Something that lots of people don't know is that the Summoner's final area shows you which tomb. There are always six glowing symbols there, and the one that's not shown is the true tomb. Initially Blizzard was going to just have that, and players would have to figure which one wasn't shown, and go to it. However they made all of the quests much easier in testing, until in the final game you just had to enter the Canyon and then check the Quests menu to have it tell you which tomb to enter.
December 9, 2000
- A feature of Diablo II that some people don't know about is that many quest items can be gotten again, after they are initially awarded. If you lose your Horadric Cube, one of the Zakarum High Council in Travincal will drop one so you can use it to transmute Khalim's relics. In Act Four, Cain will give you a new Soulstone every game (if you don't have one) when he gives you the Hellforge quest, until you complete the quest.
Cain seems to have an endless supply of Mephisto's Soulstones. This was something Blizzard added in when in testing people would often not pick up their soulstone from Mephisto's corpse, or else would lose it or drop it before they got to the Hellforge, and then be unable to complete that quest reward.
The reward was often skipped in D2, since it was just gems which everyone had tons of after a little while. It's much tastier in D2X with the random mid to high level Rune on Nightmare and Hell. Most players have gotten a lot of their best Runes from this quest. I've seen as high as Lo, #28, on Hell, and you can get Um, Ist, Lum, and all the other useful ones as well.
December 19, 2000
- A useful bug/feature of Diablo II is that quest items aren't in any way marked or tagged with the difficulty level they are earned on. This keeps you from having two of the same quest item at a time, but it can be somewhat exploited by saving a quest item, such as the Horadric Staff or Khalim's Will, and using it later on a higher difficulty level.
This is now common practice, with most players skipping the Act Three Book quest in normal or Nightmare, the once they reach hell going back and doing it, and bringing the book to Hell, since that's much easier than entering the often stair-trapped Ruined Temple in the Kurast Bazaar.
You can also save the staff in Act Two, if you are in a party and more than one person has it, all will vanish when they socket it in the orifice, so mule it off to another character, and get it back for Hell to save time.
December 28, 2000
- There are three quests in Act Four, but you only need to complete the 3rd one, killing Diablo. Killing Izual is a popular one as well, for the big 2 skill point reward, but many people dread the Hellforge quest, especially on Nightmare or Hell, where Hephasto can be the most dangerous monster in the entire game. That quest is fully optional, if you don't want gems you can freely skip it, though Hadriel suggests you do it if you click on him.
Hadriel is the angel you see just before entering the River of Fire causeway, on the way to the Chaos Sanctuary. Hephasto was a terror in D2, with his extra strong hits doing massive damage. He could routinely do 800 dmg on Hell, and with most characters having fewer hit points than that, a one hit death was very possible. Teleporting Hephasto was just not done, other than by some very big hps Barbarians, or brave Bowazons. Extra Fast Hephasto was a death wish also, as he could usually outrun you.