I was recently musing on whether it would be possible to play AlienCity with just piecepack (that is, without IceHouse pieces).

In addition to a standard piecepack, Alien City requires five large red, five large blue, and four large green Icehouse pieces for towers, and six small Icehouse pieces to cap the towers -- three in two different colors (in my group, we usually use black and clear, because we have them packed in the same bag as the four basic Icehouse colors of red, green, blue, and yellow). Is there a way to replace these Icehouse pieces with piecepack pieces?

You can play Alien City with two easily discernible piecepacks, such as a wooden piecepack and a plastic piecepack, or a StackPack (two piecepacks of different sizes). The coins from one set would represent domes and the coins from the other set would represent towers, which are usually Icehouse pieces.

Alternatively, if you had two identical piecepacks, you could still use one set of coins for domes, as usual, and another set for the towers. However, you would need to mark some of the coins in some way to distinguish them. You could distinguish domes from towers by orientation -- how the coins were rotated -- but they might be hard to distinguish visually. A better suggestion might be to raise the coins representing towers somehow. You could stack them on top of coins from any other piecepack, for example. If you didn't have a third piecepack, you could use pennies or other small currency. For tower caps, I suggest one player should take three dice of any suit and the other three pawns. This would make the sides even more visually distinct than in a game with Icehouse pieces.

Thus, it seems the most you really need to play Alien City is two standard piecepacks and some markers such as pennies. This shouldn't be surprising, as Alien City has been played with homemade purpose-built sets, on the web, and in virtual reality, among other ways and places. Like Chess, it seems the game is so immersive, you can probably play it with sticks, stones, and sand on a desert island.