The real property trading board game (apart from having no board)
The player with the highest score wins when the game ends. Score is the victory points they've accumulated by then, plus the standard price value of all their moons. Game ends after the round in which someone builds the last (twelfth) hotel.
There is no board and the players have nothing but ownership markers to put on their moons when they get some. There are moon cards in 4 suits for the moons of each outer planet: 12 for Jupiter , 9 for Saturn , 5 for Uranus , 2 for Neptune .
There are heaps of money used as victory point markers, and a supply of 32 houses and 12 hotels. The player who last bought a moon in the outer Solar System goes first, or it can be decided randomly.
The moons for each planet are arranged in a very specific way, forming one or more rows in which each card 'above' the first row needs to be supported by two cards under it, leading to pyramid structures. E.g.
Cards moving to a row are added at the right hand end, and when a card is moved or removed its gap is filled by moving other cards from the right. If an action would cause this and it leads to any cards being unsupported, the action is not allowed.
A round is a turn for each player. Players can mostly only do things in their own turn, except when their moons are activated by other players in their turn.
A player turn consists of choosing two dice to roll from the set of D6, D8, D10, D12 and 2xD6, rolling those dice, activating a moon with the number rolled on each, if possible, and optionally selling a moon for the standard price to the bank after that, making it unowned again.
The activating player chooses one moon for each roll (which can be the same for both rolls if they produced the same number) in either order for one activation, with various possibilities according to circumstances.
Most sorts of activation can be done with either or both dice, but only one claim and one buy (including one of each) per turn. In particular, this makes it impossible to use both dice on the first turn, reducing first player advantage.
Claim (only an unowned moon)
Buy (only a moon owned by another player)
Build House (only on an owned moon with 0-1 houses)
Build Hotel (only on an owned moon with 2 houses)
Move Moon (only on an owned moon)
Build Facility (only on an owned moon with enough houses/hotel and room to move)
Gain Victory point (only on an owned moon with a hotel)
Activate Supporting Moons (only on an owned moon with a facility)
Rent a Moon (only a moon owned by another player)
Mine an Asteroid (only an owned moon matching the asteroid's mining number)
Only an unowned moon can be claimed and there is no cost. It is placed in the moon layout of cards for its planet, at the right hand end of the first row of cards, and marked with one of its new owner's marker.
Only a moon owned by another player can be bought, and the cost in victory points is the standard price plus 1. Buying does not move a moon or change its contents, just the owner marker.
Add a house to the owned moon if possible, a moon can contain only 0, 1 or 2 houses. Houses are needed to become a facility, and as steps towards replacing them with a hotel.
An owned moon which already contains 2 houses can be upgraded by replacing the 2 houses with a hotel, if one is available in the supply. A hotel is useful for victory point income and for fourth row facilities.
An owned moon can be moved any number of places to the left within its current row, displacing other moons in the row to the right as needed.
An owned moon with enough houses/hotel can be upgraded to contain a facility, by moving it to a row higher than the first, if there's a supporting position for it and closing the hole at its previous space doesn't cause any unsupporting problems. The moon needs at least 1 house to reach the second row, 2 to reach the third row, and a hotel to reach the fourth row. The facility keeps its houses or hotel.
Gain Victory Point
An owned moon with a hotel can generate a victory point for its owner.
A facility can activate all the moons in the first row that are supporting it, however indirectly, in order from left to right. Each is then activated by its owner, with the same choices as if it was activated by die rolls.
Mine an Asteroid
An owned moon can be used to mine an asteroid if the moon number matches the asteroid's mining number. Mining gives 2 victory points.
Rent a Moon
A moon owned by another played can be rented for 1 victory point, and activated as if owned - except for not building a facility on it.
Asteroids are represented by dominoes, with two different numbers from 1 to 9 - there are no blanks or doubles. The higher number defines the moon(s) that can mine it for 2 victory points. The lower number defines the target moon that the asteroid will crash into at some time.
There is a separate asteroid for Jupiter and Saturn, each replaced when it is diverted.
The asteroid can be mined as many times as its mining moon number, and then crashes into the target moon, destroying any houses and hotel on it. The target moon can eliminate the asteroid with a divert action before that.
Moons are valued for various purposes with a price in victory points roughly equal to the number of activations the moon took to reach its current state. That is, 1 for being claimed, plus 1 per house, plus 3 for a hotel, plus n for a facility in row n+1.
Change hotels to facilities, can only be built when promoting from first row, and produce cash as alternative to delegation. Allow more houses, need something for them to be for. Then asteroids can destroy all houses, leaving hotels in orbit. Hotel needs as many houses as its level to activate.