I’m in the process of creating a sandbox using the implied OD&D setting. I’m not sure if this will turn into a game or not; it might just end up being an exercise. While working through this process, I’ve gone through the booklets several times now, and it has got me thinking again about what makes up the essence of D&D. Just about all the things that I now consider important to the game are here in the beginning. I think it’s valuable to see all the parts working together before you start to swap out bits, and I’ve never really done that systematically. So, paradoxically, in order to investigate hacking D&D, I’m doing the opposite.

Here is a summary of what the 3 LBBs cover, and how much space is dedicated to each topic. The space allotted to some topics is surprising.

• Men & Magic
  • Classes; Fighting-Men, Magic-Users, Clerics (2 pages)
  • Demihuman Races; Dwarves, Elves, Halflings (1 page)
  • Alignment (1 page)
  • Abilities and character creation example (3 pages)
  • Hirelings; negotiation, monsters as, loyalty (2 pages)
  • Inheritance (1 page)
  • Equipment (2 pages)
  • XP tables and advancement (4 pages)
  • Combat and saving throws (2 pages)
  • Spells and turning undead tables (2 pages)
  • Magic-user spell descriptions (9 pages)
  • Cleric spell descriptions (3 pages)
  • Magical research and spell book rules (1 page)
• Monsters & Treasure
  • Monster stats reference table (2 pages)
  • Monster descriptions (17 pages)
  • Treasure types (1 page)
  • Magic item tables (4 pages)
  • Magic swords (4 pages!)
  • Other magic items (8 pages)
  • Artifacts (1 page)
  • Coins & gems (1 page)
• The Underworld & Wilderness Adventures
  • Dungeon maps, traps, dungeon stocking (4 pages)
  • Movement, time, surprise, dungeon encounters (2 pages)
  • Dungeon encounter tables by level (2 pages)
  • Example dungeon session (2 pages)
  • Wilderness strongholds and their inhabitants (2 pages)
  • Wilderness encounters (2 pages)
  • Wilderness encounter tables by terrain (2 pages)
  • Evasion and pursuit (1 page)
  • Construction of castles and strongholds (4 pages)
  • Mass combat (3 pages)
  • Naval combat (8 pages)

Men & Magic contains almost all of the player interface to D&D. In that sense, it is the precursor to the Player’s Handbook. It has the character generation rules (including special powers), equipment, the way combat and advancement work and a few aspects of implied setting that impinge on PCs (such as alignment). Most modifications of this material will increase the cost of entry for new players.

Monsters & Treasure contains the risks and the rewards. It also interfaces with the advancement rules (because of XP for GP), but not in a player-facing way. That is, players know from Men & Magic that XP is rewarded for treasure, but the rules in this book encode the frequency and distribution of the rewards. Several subsystems (such as dragon subdual) are described here, which PCs should probably know about, but these can easily be introduced diegetically within the game as necessary. This material is relatively modular and it easily swapped out for custom monsters and treasures.

The Underworld & Wilderness Adventure encodes the three different game modes. These modes also correspond roughly to three different campaign phases: low-level dungeon crawls, mid-level wilderness adventures, and high-level domain rules (stronghold building and mass combat). Each of these modes makes use of the previous mode (for example, mid-level characters still have encounters in dungeons or rooms). This book is almost entirely for the referee (and thus is a predecessor to the later Dungeon Master’s Guide), and provides tools for setting building (stocking dungeons and generating NPC strongholds). The evasion rules probably count partly as player-facing rules. The mass combat rules should also probably be considered player-facing, but most games don’t actually get to that stage in my experience.

So what is the core of D&D? The aspects of characters that are class invariant (ability scores, mostly). The way combat works. The advancement system and incentives (that is, what is XP rewarded for). This makes up 10 to 12 pages depending on if you include equipment. The domain rules if your campaigns reach high levels. Classes and races are extra character generation options; the core game can be played without them (18 of the pages in Men & Magic are dedicated to classes and spells). Hirelings and inheritance rules occupy a strange place in the rules. Superficially, they look like setting details that are included here because they are part of the player interface, but in terms of how the game plays they are probably more integral than classes and special abilities like spells or turning.

Consider Carcosa as a case study. It is built on Men & Magic, but the only classes allowed are traditional fighters and the new sorcerer. Monsters are mostly custom (though there are a few creatures in common with the traditional game, such as mummies and oozes). Treasure is replaced with space alien technology and ancient technological artifacts. The underworld is only hinted at obliquely, but the wilderness is given by example (hex descriptions) rather than formula.

Thus abstracting the sections marked out above, this is what you might replace when building your own custom version of D&D:

• Player’s Interface
  • Classes & races (and powers such as spells)
  • Equipment (this implies places to buy equipment)
  • XP incentives (this will determine the type of adventures)
• Referee’s Interface
  • Systems
    • Time keeping and resource tracking
    • Non-combat resolution (searching, traps, etc)
    • Encounters; surprise, initiative, etc
  • Setting
    • Bestiary
    • Treasures
    • Encounter tables by terrain type or region
    • Map or terrain generation system
    • Dungeon and dungeon stocking guidelines
    • Hex stocking system (not really present in OD&D)

I believe the above list to be entirely genre-independent at this level of abstraction, though you may need to add other layers of maps for games that allow space travel. If you work through those elements, my thesis is that you will have the smallest complete setting that could potentially satisfy all aspects of the original game. Am I missing anything?

Surprisingly, the part of the 3 LBBs that feels most lacking to me is actually the part that I also think is most unique and valuable, at least compared to other similar games (because it’s usually totally absent): wilderness stocking rules. TU&WA punts by only giving you half of a system. The referee is instructed to get a copy of the Wilderness Survival hex map (page 15):

OUTDOOR SURVIVAL has a playing board perfect for general adventures. Catch basins are castles, buildings are towns, and the balance of the terrain is as indicated.

Then rules are provided for generating the inhabitants of the stronghold and for interacting with the stronghold (including very interesting guidelines for the occupants venturing out to meet adventurers). And random encounter tables are provided for other wilderness inhabitants. Now, this is not bad, but I still find myself somewhat blocked when I go to create a wilderness area. Basically, I think the wilderness setting guidelines in the 3 LBBs are more example than generator, so anyone that is building a setting from scratch will need to come up with their own system (something similar to the dungeon stocking system is what I am experimenting with, but it still requires some modifications).