Thought of an improvement to my earlier post, The game is set up by placing a grid of face-down resource cards and then a face-down cardboard tile over each card. The face-up side of the tile has one of several passages on it such as 90 degree turns, straits, 4 and 3 way intersections etc along with map features like lakes, chasms, caves etc. When a player mines a tile they remove it and take the resource card underneath (this could be some valuable ore or gems or just plain stone or maybe something bad). They must then place the tile back into the spot (they can choose any legal rotation of the tile), to be legal a tile must connect with all adjacent flipped tiles that are connecting to it. In other words the only permissible dead-end is one facing an un-flipped tile. If a legal tile can not (or will not) be placed the new tile 'collapses' and the players tile is instead put face-down and the any player adjacent to the collapse suffers damage, but they are allowed to keep the resource card which is not replaced.
Miners have a unique advantage, they are dealt 3 face-up tiles for their exclusive use. When they mine a tile they add it to this set and may then choose any of these tiles to place back into the excavated spot, they can even choose to cause collapses intentionally just to switch out tiles. This means the miner is able to exercise a much greater degree of control over the tunnel direction and organization and do so in a much safer manor. A speed advantage might also be appropriate as well, likely the miners mines without expending movement points while others do.
Other professions would follow a similar pattern, everyone can DO the action but a special rule or bonus gives a professional an advantage and most importantly interesting decisions to make. Changing professions is possible but hard, the player must spend 3 turns in a row doing the activity of the new profession during which they receive no bonus, at the end of the 3rd turn they may choose to adopt the new profession. Only one instance of each profession is allowed so the player can not switch to a profession that is already in use.
The players are all going to be struggling to stay alive, they need food and alcohol and have limited health. Each player starts with 7 each of drink, food and health tokens. Each turn they lose either a food or drink token (their choice if both are available) or a health token if food/drink are exhausted. Combat or other nasty events can take away health tokens directly, when all health tokens are gone the player dies. They can only re-enter the game if the remaining players can attract an immigrant (probably done by expending some wealth) and will come back as a no-skill peasant though they are then eligible to learn a profession.
The player is limited to keeping 7 resource cards in their hand. These include worn equipment, weapons and tools along with pets and domestic animals, crafted items, raw materials and consumables. All of these can used/consumed at any time, food items and drink items are labeled with how many food/drink tokens they provide which would range from 1 for a Plump-helmet to perhaps 4 for a wheel of cheese. Players can place resource cards on the board under their character but only one such card on each tile unless a stockpile has been made in-which case up to 7 identical cards can be placed, players can pick up cards from any tile they move over and do exchanges if their hand is full. Players in the same tile may exchange as many cards as they wish. Anything which moves/exchanges resource cards without changing or consuming them is a free action. Consuming or changing resource cards generally ends a players turn.
Workshops, stockpiles, traps and various useful structures can be built by any player by expending a few building materials (wood, stone, clay) and replacing the original tile with a workshop tile taken from a separate group not used when the board is set up. Professionals can build their designated workshop as a free action while others expend their whole turn to do so, workshops all act to make a particular action taken in them better/easier. All workshops are dead-ends and can placed only on existing dead-end tiles, in addition doors can be placed in strait tunnel sections, they can slow-down hostile creatures which must pass a strength roll to move onto them. Traps are a bit more flexible and will be available with corner, 3 and 4 way intersection instances. Trap tiles have a 'set' and 'sprung' side and are flipped over to indicate their change in state. Mechanics can make more and better traps and can reset them as a free action when they pass over them.