I recently bought Roll for the Galaxy. The game doesn't offer a solo mode, but thanks to the community there are unofficial rules for one. I started with some simple rules I found on BoardGameGeek and tried to conquer the galaxy alone.
The rules are not actually called "simple rules", it is what I call them. The reason is - as you might guess - because they are really simple to understand and do not require a lot of bookkeeping during play.
You play against an AI player. The way that works is, you roll a white worker die after you have selected your phase - during the reveal step. The phase of the rolled face will also be choosen during this turn. If you roll the same phase you have choosen, no additional phase will be played. When the rolled phase comes up, the AI acts, depending on the phase:
- Explore: the AI gets 1 VP chip
- Develop: the AI draws a tile and adds it as development to its tableau
- Settle: similar to Develop but with the planet side up
- Produce: the AI gets 2 VP chips
- Ship: same as Produce
The game starts with 24 VP chips - same as a 2 player game and ends in the usual way. There are some additional rules, if you got the expansion, but they are really simple too.
The simplicity comes with a price though: Randomness. If you look at the actions the AI takes, it will get at least 1 VP in two out of three times. This acts as a sort of clock, which is okay. The problem is, that strategies involving getting VPs fast, are not really advisable. The AI will be able to get more VPs faster (especially early on). Also, when the AI settles or develops, it can get 6 point tiles also very early on. You can't really form a strategy on the basis of the tiles the AI has either, because it will act completely random. Which differs greatly from a multiplayer experience, where you can try to anticipate moves from your opponents - especially when it comes in choosing phases.
There's a variant of a "Personality": Instead of using a white die, you use a die randomly drawn from the AI cup. So you might get a colored die, that has slightly different chances for the phases. In the end, this doesn't change much from the randomness standpoint and might be even more "unfair": red and brown dice are really good for settling and developing and if the AI draws a lot of 6 point tiles, this can get out of hand very quickly.
On the bright side: These rules are really good, if you try to learn the game. The rules are simple and fast so that a single game takes less than a multiplayer one. There isn't much upkeep to do, so you can concentrate on the actual rules of the game and not any special rules for the AI. And since the games are quick, you can play multiple ones in one sitting.