At another forum, Teazia wrote "I suspect there are a few more mechanics involved that make it richer that have yet to be put in the preview document." Here is the list of enriching things I put together - Teazia is quite right that I should have mentioned this in the backer update, but posting here will have to do!
Things that made it richer in the Brooklyn games:
- ACKS wilderness encounters. It was very interesting when the party that brought a ballista to the dungeon knew it meant facing two extra checks in the mountain. Wilderness encounters led to three groups that tried to profit off of dungeon visitors - some little humanoids that fled, the bandit remnants of the Iron Thorn mercenaries, and a dozen ogres - plus a roc that scared away the bandits into the tunnel chewed by the herd of gorgons from the second session's encounter.
- A science fantasy approach to understanding the rules of the OD&D mythic underworld - orcs that spawn from a meat-grinder, doors made of regenerating metal that must be magicked or smashed open.
- Different parties selling maps of their explorations and hiring from the same pool of henchmen, who hung around town spreading rumors of their discoveries.
Things that aren't in the drafts so far:
- Campaign-specific wilderness and dungeon random encounter charts
- Many details of the dungeon environment and history only hinted at in the key
- Many magic items like thulian chain and the scarab of death
Things that are design goals for the ACKS conversion:
- Balancing the amount of treasure, the XP from combat, and the risk of interference from rival parties
- Establishing the local economy into which PCs will sell Thulian artifacts and predicting the disruptions likely to result
- Providing context for local politics, establishing at which point the PCs become the baddest mofos in the sandbox