MultiToSolo

The MultiToSolo frame is a collection of ways to make a multiplayer game enjoyably playable by a single player. Not considered here is playing a multiplayer tabletop game against a computer AI.

See also SoloToMulti.

Note: It's possible to "pipe" the MultiToSolo frame into the SoloToMulti frame, in effect turning a multiplayer game into a solitaire game and back again. Example: Taking Chess problems (MultiToSolo) and solving them in timed competitions (SoloToMulti).

Two-handed play

Two-handed play is well known in the world of Chess, where "walking around the table" and playing the other side is far from unknown historically as an amusement and a means of study. Two-handed play can help you to become a better player. It's a good way to learn a new game.

A richer experience can be had by deciding ahead of time what strategy you want each side to play. Also, because time between moves can help the experience, players often find it better to make a move or two at a time, and come back later. In that case, it's useful to have a way to mark which side's turn it is on the board, such as a small, distinctive token.

For two-handed play, some people prefer "asymmetric games" with different goals, such as Hnefatafl, in part because it is easier to keep the sides separate in one's mind.

Playing cooperative games two-handed is also popular, especially if the games are without hidden information, such as Pandemic or Arkham Horror.

Automa

Automa, or "bots", are "artificial opponents", rules that a solitaire tabletop player can take that simulate an opponent, to make solitaire games more fun. For example, the Princess Dorothy variant is a simple and effective automa for the game Kingdomino.

Automa don't have to be overly complicated. Consider the Go automa suggested in a thread on BoardGameGeek:

...you could make a solo variant by placing enemy stones in a predictable way after your own placements. For example: when you place a stone of your color, you must "shoot" an enemy stone from it in each of the four directions, as far as possible, without going over any other stones.

Oracles

Oracles are similar to playing two-handed, but with a simulated opponent that is like an automa in some way. However, this simulated opponent is not entirely rules-driven but requires some thought and interpretation on the part of the solo player, much like Tarot or the I Ching, but without any occult connotations.

Another difference of oracles from automa is that oracles tend to be universal, in the sense that they can be used with almost any multiplayer game, whereas automa can only be used with one specific game. For example, the Kingdomino automa mentioned above could not be used with Chess or Terraforming Mars.

The gold standard for board and card game oracles is the SoloSystem by Chad Mestdagh, which was influenced by an earlier roleplaying game oracle called the Mythic Game Master Emulator. Other board game oracles include the following:

Solitaire variants

A solitaire variant of a game is a game that uses many of the rules of the original but is scaled down to suit a solo player in some way, for example, by changing the victory condition. It's meant to give a taste of the original game without necessarily approaching the full experience.

Take two solitaire chess variants as examples, Queen's Quadrille by KarenDealRobinson? uses most of the pieces of Chess, which move as usual, but on a smaller board with a victory condition more like the 15 Puzzle. In her Chess Contradance, the pieces (not counting pawns) appear on the board in their usual positions with their usual moves, but the goal is to maneuver each piece to its corresponding space on the other side of the board.

Game problems

Game problems are familiar to many people from Chess problems and Bridge columns, both of which used to be published daily in some newspapers.

A game problem is an artificially created position in a game, with a requirement that the player resolve the position in a particular way. For example, in Chess problems, the player might be required to checkmate the opponent in a given number of moves.

Chess and Bridge are not the only games for which people have published problems. Consider (for one) the chess variant Ultima, which is actually not very like Chess. Also interesting is the book Your Move: Logic, Math and Word Puzzles for Enthusiasts by David L. Silverman, which is a collection of game problems, most of which are not for Chess. Finally, RonHaleEvans? has collected a large and expanding number of web bookmarks to game problems, books of problems, and so on.