I was going to post this in one of the celebratory threads about the 20th anniversary of 3rd edition, and decided that it was too tangential and thread-cappy to go there. So I am putting it in its own thread so we can discuss (if you feel like it).
I'm not an expert historian about TTRPGs and I've only been in the hobby since the late 1980s, so there's much about the early days I don't know. The original lineage of D&D seems to be OD&D (1974) going through the BECMI line into the mid-90s or so (with some slight revisions, but being mostly backwards compatible and compatible with AD&D). Then AD&D 1e was released in 1977 and was only slightly changed in 2e, which lasted until 2000 (when 3rd edition was released). 3rd edition was such a departure in gameplay that it had no connection or compatibility between any of the previous editions.
YMMV. To me the single biggest fundamental change was from 1e to 2e - which means if your thesis is valid then D&D died when Gygax left.
The reason AD&D changed between 1e and 2e in fundamental ways that even the 3.5 -> 4e change didn't come close to is that the play the rules incentivised changed. In AD&D as part of the core rules you gained 1XP for every GP you obtained. This meant that the playstyle rewarded by 1e wasn't murderhoboing your way through everything because killing monsters was your main source of XP. It was loots, heisting, and robbing the monster lairs blind when they weren't home with smart play involving both lowering the risk and taking things fast because wandering monsters, far from being wandering bags of XP, were 100% of the risk of normal monsters but because they didn't carry treasure were only 20% of the XP reward and so to be avoided.
There was also a second fundamental change - 2e almost took out the early game when you brought your hirelings with you in low level dungeons. Charisma (which capped hireling numbers) was a hugely important stat and the low level wizard was effectively a platoon radio operator. Also 2e more or less took away the soft-cap on the levels when the fighters got their titles and lands and the wizards got their towers at level 9 or 10.
Here are some of the biggest differences that I was hung up on when first learning 3rd edition:
1) tactical movement on a grid
As opposed to tactical movement on a table with measurement in inches? Is that what you are saying changed? And don't get me started on the ridiculous AD&D fireball rules with a fixed volume so even the caster might not know where the boundaries were and that to handle fairly needed a map.
Seriously, all D&D editions use either wargame or boardgame measurements. And there's precisely one reason that 4e is the hardest version of D&D to play Theatre of the Mind - and that is forced movement meaning that the terrain and tactical positioning are just more relevant in 4e because throwing people into or off terrain (like campfires or docks/piers) is something very easy to make happen with lower opportunity cost in 4e.
2) attacks of opportunity (for nearly everything)
Expanded - AoOs used to be for leaving combat and for spellcasting in combat. Definitely there since the start.
A definite continuation from Skills & Powers.
This was something largely broken by 2e changing the fundamental nature of D&D.
The reason AD&D used different XP tables for different classes was class balance. But balance was along an axis. Bringing class balance back was a part of resuscitating D&D.
Monster Level.
6) 0-level spells, cantrips, and ever-present spells
7) prestige classes
Cantrip is literally a 2e spell. 0th level spells are not a fundamental change. Prestige classes were mostly new although the 1e Bard was for all practical purposes one.
8) the d20 DC system for skills (that took away all DM rulings, as everything was codified)
It hardly took away all rulings. But yes, this was a fundamental change made in 3.0/3.5 and then reverted by 4e.
9) character wealth by level baked into the system
When you got 1XP for every GP you earned and smart play involved going after XP rather than levelling up by killing then wealth by level was for all practical purposes baked into the system.
The game looked different too. The art style was no longer based in fantasy illustrations, rather than "this is D&D 'dungeon punk' and it can't represent a character from history, fantasy fiction, etc."
I'm not presenting this as a value judgment. I like things about 3.x - the present. But it seems to be that the game forever shifted in 3rd edition. I can't even run the games in the style I used to 20 years ago or play characters the same way. I don't think anyone does in modern D&D.
The problem here is that you are operating under the misunderstanding that 2e was the same as 1e. It wasn't. 2e was an attempt to sell new wine in old bottles, a different fundamental game from 1e in which what you were incentivised to do was very different. But they kept most of the
irrelevant details such as descending AC the same. Meanwhile 3.0 launched under the "back to the dungeon" tagline and attempted to bring back things that had been taken away by 2e to mixed success.
Anyone else realizing this?
That the game has changed with every edition? Yes.
Also that the game has been a continuation of the trends of the past with every edition? Also yes.
Also that every edition is an outlier depending on what you value? Also yes.
Also that many, many people think that The D&D They Learned is the One True D&D? Once again yes.
And the thing is that
they are all sometimes valid. But if you start saying "D&D died after my version" and your version is anything other than the brown box (or possibly the white box) you'll get told by those playing a previous edition that you're a damn kid who should get off their lawn. Not because the people who've been there longer mind kids on their lawns but because if you're running the "older is purer" your version certainly isn't.
And I am serious that the biggest fundamental change was the change in default XP rules from 1e to 2e and the next biggest was the deprecation (1e->2e) and removal (2e -> 3.0) of the hireling and domain rules. Of course the Shameless Cash Grab Edition award after all these years still belongs to AD&D 1e's deliberately being created to screw Arneson out of royalties.
There are new things under the sun but changes are both bigger and smaller than we realise.
