In the beginning... there was vanilla WoW, which had no badge system, or heroics for that matter. After you hit the level cap, you could do some gearing up from drops in normal five-man dungeons, but that was pretty much it.-Shintar
Did you catch it? Right there, at the end: "pretty much it." That pretty much it covers quite a lot!
Technically speaking, vanilla did not have heroics. But let's go pick apart some details, see what we can find between the hairs I'm splitting.
What were the vanilla heroics? Well let's see what a BC+ heroic is. Same instance, with trash and bosses that hit harder (irrelevant given relative loot levels), some slightly higher loot, and maybe another boss.
We called it tier .5
Officially it was Dungeon 2, but that was too easy to say compared to tier .5, and back then we believed in challenging ourselves. I once saw someone get hacked and deleted because he said "deeps". We had standards. "This type of item set is sometimes incorrectly referred to as "Tier 0.5" by players." See, I'm right.
In a nutshell, this was a long and expensive quest chain which required players to gather the full dungeon 1 set (sometimes we called it tier 0, for no good reason), and then through the quests, resulting in a half-epic set of overall higher quality, though still inferior to the tier 1 that came from Molten Core. What made this heroic?
"Same instance, with trash and bosses that hit harder (sometimes irrelevant given relative loot levels), some slightly higher loot, and maybe another boss."
The quests were all either outside (not phased) or in the usual instances. Trash was unchanged, except in one case which I'll get to. The quests upgraded the sets and required summoning new, otherwise inaccessible bosses, which dropped some special loot of their own, including pieces of a strange early attempt at a PvP set.
The new fights were not especially hard, but could at times challenge a group, somewhat like heroics not during LK. There is a notable exception, a quest which required the undead side of Stratholme (minus some trash) to be run in 45 minutes. This was not a trivial task. The place was filled with patrols that needed to be handled carefully, due to their tendency to pull adds and fear players. There was not enough time to kill all the trash, so players had to carefully pick pulls, skipping what they could, but knowing that screwing up would be more than a minor inconvenience. If you remember the special bonus at the end of Shattered Halls in BC, it was a bit like that, but harder due to not having an efficient AoE tanking class.
That's pretty much it
Vanilla had more horizontal progression. Or at least angled. Crafters could gain some impressive profits from particular reputations. Mounts weren't in a cash shop, but also in grinds, or luck. World drops mattered forever in a time when we didn't outgear them a month after release. There were ways to progress that did not involve a raid or a random heroic. I liked that. Somehow, some people didn't. I do not understand those people.