Mine-Shaft Gap (2006)

Mine-Shaft Gap simulates a battle for resources on, above, and under the surface of a lifeless but treacherous planetoid. Players must seek out valuable metals and fuel materials and mine them, using the materials to feed their home planets, and inch closer to victory, while at the same time allocating resources to maintain or strengthen their armed forces and fortifications. Drill tanks tunnel beneath the surface of the planet while drilling stations pound away from above. Drilling stations are faster and more efficient, but are vulnerable to attack from above and even capture by enemy troops. But tunnels can cave in… And market forces are unpredictable. The resource making your planet rich today might be better off greasing the treads of your tanks tomorrow!

The game takes place on two maps – one representing ground level and above, the other representing underground terrain. The rules differ slightly depending upon the map on which action occurs. At the beginning of the game, the subterranean map is unmarked: it is solid. As the game progresses, units will drill beneath the surface of the planet, creating tunnels through which they and other units can explore the sub-surface, mining for riches and engaging each other in combat. Each map parallels the other, in that each hex on one map represents the same coordinates, just at a radically different elevation (above or below ground) on the other map. Maps are labeled in columns and rows so that it is possible to find corresponding hexes quickly. Hex B4 on the surface map is considered to be directly above hex B4 on the subterranean map, and so on. It is recommended that a new subterranean map be printed out for each game, so that it can be marked throughout the game and discarded at the end.

Counters represent mobile units such as drill tanks, transport vehicles, hovertanks, missile launchers, atmo-craft, and squads of infantry with jump-jet powered armour; structures such as command posts and drilling stations; extracted resources; and rubble. They are printed with varying information. Resource counters show the type and quantity of resource with a letter and number. Units are printed with a movement type, attack strength, range, defense strength, and movement points.

Elements include tactical level sf combat using a terrain-and-elevation-based combat system, satellite searches for ore deposits, in-game allocation of resources to build units and outposts, resource extraction and re-use, resource allocation towards victory, varying resource value depending on market fluctuations, airstrikes, cave-ins, and underground combat.