Alternate Mine Warheads.

[dmm]

PsychoTF: I may be mistaken, but I think that if the MS doesn't sweep all the mines, then the ones remaining try to blow up the MS. So then any ship would remove all of your dummy mines simply by triggering them.

The only use for dummy mines would be if the enemy fleet somehow saw them before entering a sector, and was too scared to attack immediately because it didn't have a MS along. Is that possible with long-range sensors? But then the sensors would reveal that the mines were dummies, so you're back to square one.

I think you'd be better off with dummy fighters, which ARE visible on the strategic map. That would make for some good after-game bragging! "Hey loser! Remember that heavily-defended system, the one with 100 fighters per planet? The one you left as fast as you could? Guess what? They were all FAKES! Hahahahhahah! Loser, looozzzer!"