With Old School Essentials and Swords & Wizardry, why do I need Adventures Dark and Deep?
ADAD is a huge game. This is the ultimate version of the first edition, and it does not even belong in the same class as OSE or S&W. This is a big book game, with everything you would ever want in it, looking through a detailed, stat-heavy, and complete first-edition lens. It is so comprehensive and massive that there is only one game it could compete with.
ACKS II.
ACKS II is a game just as large, just as ambitious, just as complete, and just as compelling as ADAD. Both are in the heavyweight division of gaming, and these two massive games can slug it out for tabletop dominance. Where ACKS II is the Bronze Age powerhouse of savage lands and the wickedness of chaos tearing apart civilization, ADAD is classic first-edition gaming at its best.
ADAD is gearing up in town, wandering through the woods and avoiding deadly encounters, and prying open the lost tomb's sealed entrance to delve inside. It is the slow grind, every bonus matters, count the coins of encumbrance, and full-bore first edition game, plus so much more. The game expands our knowledge, with page after page of what could have been. And it reflects the future, some, while keeping its boots firmly planted in the golden era of roleplaying.
ACKS II is the tale of conquering kingdoms. Zero to hero, or diabolical villain. Savage lands, conquering cities, raising armies, and rebuilding civilization. It is equal parts brutal, beautiful, notorious, and glorious, with iconic heroes and vicious creatures of myth and legend.
So, why ADAD? Isn't the rules-light S&W close enough?
ADAD features classic monsters, classic presentation, and tons of additional content inspired by years of research and inspiration. This is the big "what if" first edition got a proper second edition, but it was done by the original creator. And then, the game evolved into its own thing, no longer a fantasy "second edition" but a distinct game in its own right. We offer new classes, including magic, monsters, and races, as well as various other options. We have a skill system. We have so much more than the original books, and it would take years to explore them all.
And really, we have the best of everything in this game.
Not to mention a wealth of excellent add-on books and adventures from the same creator. If you like the classic "stuff" and that retro crunch, this will be a new favorite game. The Swords of Cthulhu book is not to be missed, and can feed an entire campaign's worth of action fighting against elder gods as first-edition heroes.
Both games are similar in that they limit character race and background options. ACKS II offers a diverse selection of humans, while AD&D offers the classic races, plus a small number of new ones to try. If you don't want a bunch of silly talking dragons, half-demons, and other modern distractions, both of these games will challenge you to be diverse in a smaller set of options. The more I limit race choices to the classics, the better the diversity of people represented at my table becomes. ACKS II is a master class at including setting-specific, heroic, and noble backgrounds of diverse cultures in the setting, yet they are all humans. ADAD is the classics plus a few new ones.
ADAD feels like the real thing, plus everything that could have been. It is like AD&D 2nd Edition never happened, and the world kept moving on with the original first-edition game. The game hasn't been streamlined; there is no THAC0. We write down our to-hit numbers on our character sheet by AC numbers, and all our stats have these wonderful secondary modifiers.
Grappling hooks have their own chart, which determines different percentage rolls based on the object they are trying to grab onto. Additionally, some results have a chance to slip off after a random amount of time passes. That is wonderful, first-edition, pedantic, nerd-delighting, wonderful nuance and detail. This is why I play this game. If something can happen, it has a chart somewhere. If it doesn't? I will create one that generates a set of fun, random results.
ADAD is about every last detail, minor modifier, and rolling on a chart for something, somewhere, for almost anything.
It is like Dungeon Crawl Classics in a way, only the charts are not wild and gonzo results, but all manner of great and terrible things that can happen to normal people. If there was ever a game that required a percentage chart for pulling potion bottles open with your teeth, this game would have it, or you would need to create one.
For any not-by-the-rules action, you could always roll 1d100 and interpret the result as a disaster (1), a miracle (100), or a combination of both, with failure and success being the intermediate outcomes (2-99). Modify up or down based on the ability score or situation, if needed.
Want to read an ancient text? Make that 1d100 roll.
If I did not have the energy to "drill down" into this level of detail, Swords & Wizardry is a great alternative, with far fewer charts and modifiers floating around on random pages. It depends on your tolerance for charts and modifiers, and ADAD may either be the perfect game for you or a nightmare. The rules state that you can ignore most details, and the specifics are provided if needed.
ADAD is clearly a "superfan" game, just like GURPS. If you are devoted enough and love the system, no amount of complexity and detail is too significant. Otherwise, even if you are half-interested, go for a more rules-light game, such as C&C, S&W, or OSE.
If you can be a nerd about that grappling hook table, then ADAD is clearly your game.
ACKS II is complex in a different way. As you level up and your game scales to dominion management, you start to delve into the more complicated areas of the game. The lower-level games in ACKS II are more akin to a B/X-style set of game rules in terms of complexity, making it easy and straightforward to dungeon crawl without needing extensive rule references.
ADAD keeps you in the weeds from day one.
While ACKS II went its own way with dominion-style gaming and that savage, classic, myth and legend feeling, ADAD goes back to the hobby's roots and gives us a wealth of new toys for our toybox. ADAD is like if 5E and AD&D had a collision, and AD&D came out on top.
But both games are giant, huge-book heavy hitters. There are games in the "superheavyweight class" of tabletop gaming, and these games are for some people, and not for others. Both are excellent games, and each has its place.