Mine Warfare in 'Imperium'
By Doug McNair
April 2006

Players can increase their range of strategic options in Imperium: Third Millennium by agreeing before the start of play to use these variant rules for mine warfare.

Minelayers and Minesweepers

Players can purchase minelayers and minesweepers normally during the Construction phase. The Resource cost for a minelayer is 4, and the cost for a minesweeper is 3 (cost is the same for Terran and Imperial ships). Time to build for both minelayers and minesweepers is one turn. Once built, a minelayer has an unlimited supply of mines on board. Minelayers and minesweepers move as auxiliaries.

Minefields

In order to lay a minefield, a fleet containing one or more minelayers must activate and spend the entire action segment in a system that is free of enemy fleets. The minelaying fleet may not move or engage in combat during a segment when it lays mines. Each minelayer ship can lay one point worth of mines per segment in a given system, and multiple minelayers in the same system can lay multiple mine points in the same segment.

When laying mines, the owning player places one or more minefield counters in the system, face down. Minefield counters have numbers showing how many points worth of mines have been laid in that system — place mine counters showing the correct number of mine points laid at that location. Mine points are cumulative; if a player lays mines in a system on multiple segments, he just keeps adding more mine counters or increasing the numbers on the counters. Both sides can lay minefields in the same system if desired, as long as no enemy fleet is in a system when friendly minelayers lay mines there. Once laid, mines are never removed unless swept my minesweepers.

False Minefields

A player can also activate any fleet in a system (whether it includes minelayers or not) and place False Minefield counters there (as many as desired, face-down) to confuse the opposing player as to whether the system contains a minefield or not. Such a fleet must not move or fight in the segment it lays the false minefield.

Entering Minefields

Fleets can move through their own side’s minefields freely without danger or the need to stop moving. When a fleet enters a system containing one or more enemy minefield counters (even just False Minefield counters) it must stop moving momentarily and check to see whether it runs afoul of the minefield. It does this BEFORE contacting any enemy fleets there. The player owning the minefield flips all the minefield counters in the system to their front sides and removes all False Minefield counters there. If all the counters are False Minefields, the moving player can keep moving or contact any enemy fleets in the system.

If not, the moving player then reveals whether his fleet(s) in the system contain any minesweepers, and if so how many. The moving player then rolls two dice and adds any applicable modifiers, which are:

• +1 for every mine point in the system
• +1 if the moving fleet entered the minefield on its second or subsequent jump that segment
• –1 for every Minesweeper in the moving fleet

If the modified roll is 10 or more, the moving fleet has run afoul of the minefield. If multiple fleets move together into a system with mines in a given segment, the moving player must make a separate minefield contact roll for each fleet.

Example: A moving fleet containing two minesweepers enters a system with enemy minefield counters on its third jump of the segment. The enemy player flips the counters and reveals 5 points worth of minefields plus two False Minefield counters. He removes the dummies, and the moving player rolls two dice, with a result of 5. The modified roll is 5 + 5 +1 – 2 = 9. He does not run afoul of the minefield, but if he didn't have any minesweepers with his fleet, then the modified roll would have been an 11, and he would have run afoul of the minefield.

Mine Damage

When a fleet runs afoul of an enemy minefield, the owning player must take all the fleet's ships out of the fleet box and place them on the table. The mine-owning player then rolls a separate mine attack against each ship in the fleet. For each ship in the fleet, the mine-owning player rolls a number of dice equal to the number of minefield points in the system. So per the example above, if the fleet ran afoul of the minefield, the mine-owning player would roll five dice against each ship in the moving fleet. Every 6 rolled is a hit. Resolve damage to ships normally per rule 12.8.

The minefield-owning player then flips his minefield counters face-down again, and players move on to resolving any contact and combat between enemy fleets in the system. Mines play no role in space combat or planetary combat.

Once the enemy fleets leave the system, the mine-owning player can lay more mines there normally. Minefield counters are never removed unless swept by minesweepers.

Sweeping Mines

Minesweepers can remove enemy minefield points from systems. Each minesweeper that activates in a system with enemy minefields and does not move or engage in combat during its activation can remove one minefield point from the system. The mine-owning player removes the minefield counters and replaces them with ones showing the reduced number of minefield points in the system. Once minesweepers have removed all enemy mines from a system, all ships can move through the system unimpeded.

You can download the new counters here.

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