D&D solo as a board game?

Just play Advanced Heroquest instead. It does everything that D&D does, but in a more solid system that’s not so heavily reliant on the GM, and has better tables for generating content.

The most frustrating part of playing D&D solo is handling room descriptions.  In purely random play the rooms are either completely bare, or you have to waste time rolling on a table to stock the room with non-gameable content. When playing with a module, it really depends if the room key is split out into player only read aloud text and DM only information, and how well both are written. Sometimes the player read aloud text does not have enough information to spur meaningful choices, and sometimes through no fault of the writer it’s just easy to glance at the GM description anyway. It feels easier to just read the whole text of a room key at once, but in doing so you won’t really be playing the game.

So to solve this problem I have this idea, to tie the game more closely to the board. Almost every module comes with an empty map with numbered keys. Instead of moving my characters abstractly through the dungeon, I’ll select an actual 10’x10’ area per character, move them to that location, and see if anything is there. This necessitates moving the characters through an actual space in the dungeon. Then I’ll flip over to the room key and see what is in the space around each character. If they tripped a wire or pit trap, fell into an ambush by a monster, or discovered treasure or secret door, all would be resolved after my characters first moved into the area ‘blind’.  If I do not look into the right area, or do not do the right procedure to find the hidden element in a square, then I miss it and lose the treasure, fall victim to a trap, or lose surprise to a monster ambush.

This is contrary to the way live RPGs are played and denies me information that I should “know” before entering an area, but on the other hand it is playable and keeps the fun of discovery for myself.

AD&D has more in depth rules for dungeon crawling than any other edition. The sections on movement and searching, lockpicking, and listening at and forcing open doors are the most helpful here. These procedures are tightly coupled with the time scale, so it’s important to keep an ‘adventuring clock’ to track rounds and turns, or a sheet to check them off as they go by. Accurate tracking of time allows the player to coordinate the characters’ actions in a standard way.

For random dungeon generation, this means not stocking the dungeon until after the player characters have moved through it. This incentivizes checking squares, because to do so otherwise puts me at maximum risk for falling for a trap or a monster ambush.

In the case of traps, if I choose a PC to check a square for traps, and if he hits the chance of triggering the trap, then he detects and avoids it and I can mark it on the square for all PCs to know. If I want the PC to do something else, like check for secret doors, and I roll that he gets hit by a trap, then he falls victim to it.