A Minetown (or some other town) minigame based around classic survival/area defense games:

• Takes place in a smaller-than-Minetown square walled area in a large open part of the mines.
• Orcs, with a very high spawn rate and an increasing difficulty modifier, appear around the edges of the map.
• The walls will block the weakest and the unequipped from entering the town proper, but it won’t be good once orcs start showing up with pickaxes and ladders.
• To prevent the orcs from building up a horde, there are some weaker points in the walls, maybe a gate they can try to bash down or an unrepaired breach. These must be defended with manpower and all the traps you can think to lay.
• Orcs grudge everything inside the town, and vice versa; meanwhile, nothing in the town is hostile to you.
• Shopkeepers sell you items from their limited inventory at very cheap prices.
• There are watchmen who can hold back an incursion, but they’ll eventually fail if the player isn’t able to get there in time.

A Minesweeper minigame where you start in an empty zone with a pickaxe. You can always move diagonally through gaps without dropping anything. The amount of mines next to a tile are represented by rock piles on the ground, and you can throw single rocks to embed them in walls to flag mines. Every mine hit causes an explosion that damages, wounds legs, scatters inventory, and penalizes Luck.

Elaborations on the Fort Ludios minesweeper proposal by ais523:

• Should spaces with 0 neighboring mines get 0 gold? Good because it makes the game possibly more instantly recognizable as minesweeper, bad because it makes the overall amount of gold less predictable
• Need to guarantee somehow that the person stepping into the room doesn’t trigger a mine instantly, and set up the level accordingly.
  • The column nearest the entry door could be clear of mines and gold.
  • The whole border could be clear of mines. However, this means that the total amount of gold must end up being an even number - not ideal.
• What happens if a monster steps on a mine?
• Possibly this needs an Oracle consultation to explain it to unspoiled players. Or make an engraving when you enter - possibly “xyzzy” as a reference to the cheat code in Windows Minesweeper. Or start off with one mine uncovered and identified on sight.
• The number of adjacent mines could be expressed in the ones digit of the gold amount. Possibly with a large round number added, so every space is 3001 or 2002, which hopefully clues the player into the fact that it’s a significant number. But this might be too restrictive.
• How to reach the magic number 69105, and do so in a way that guarantees it can be generated? May need to bias the level generator so that this must happen.