You can use randomized switches, but since each beacon is to be randomized once, the easiest way is to use Junkyard Dog with units.
QUOTE
Setup (all location sizes are described width x height):
2 computer players, Player and Temp
3 beacons horizontal in location "Beacons"
1 location 11x2 Random
3 locations 1x2 named Beacon1, Beacon2, Beacon3, respectively
1 location 4x4 isolated by terrain, Wander
1 location 2x2 "Check"
3 units of different types (i.e. different names), "A", "B", "C"
Place "A" "B" "C" in location Wander
Execution:
C: Always
A: Run Junkyard Dog at Wander
C: Elapsed time is at least 5 seconds
C: Player brings at least 1 men to Wander
A: Move 1 men at Wander to Check
A: Preserve
C: Player brings at least 1 "A" to Check
A: Remove 1 "A" at Check
A: Move location Beacon1 on Beacon owned by Player at Random
A: Give 1 Beacon owned by Player at Random to Temp
C: Player brings at least 1 "B" to Check
A: Remove 1 "B" at Check
A: Move location Beacon2 on Beacon owned by Player at Random
A: Give 1 Beacon owned by Player at Random to Temp
C: Player brings at least 1 "C" to Check
A: Remove 1 "C" at Check
A: Move location Beacon3 on Beacon owned by Player at Random
A: Give 1 Beacon owned by Player at Random to Temp
C: Player brings exactly 0 Beacon to Random
A: Give all Beacon owned by Temp at Random to Player