What is OD&D?

OD&D refers to the Original Dungeons & Dragons rules created by Gary Gygax. OD&D resembles something closer to Dwarf Fortress or Rogue, then Baldur's Gate or Pathfinder.

Principles

Characters start weak and must adventure to grow stronger.
The game is always on. This means that time outside of play passes according to the real life world as well. So if for instance, hiring the best engineer in the realm for your fortress takes two months, then it will take two months of real world time to hire them.
Characters are randomly generated, and a player can generate as many characters as they choose.
Drop in and drop out. Most level 1-3 Characters will want to explore a megadungeon in order to gain gear. At level 4 and higher, the game transitions to Overland play, which is more focused on stronghold management, political intrigue, and war.
Games are generally light on roleplay. Because games run 3-4 hours per session, most play must be succinct. This leaves little time for tomfoolery.
There is no predetermined story. The referee will run the world as fairly as possible. The game takes more of a simulation form.
In short, picture a dungeon crawler that turns into a 4X game. That is our philosophy of play.