Synapsen

Synapsen is a stand-alone, command-line implementation of the classic card game Schnapsen. The computer players use an Information Set Monte Carlo Tree Search (ISMCTS) algorithm to determine satisficing moves.

Synapsen is written in Python and requires Python3 or higher.

Demonstration

Usage

Clone this repository and navigate to the new directory.

Run python3 synapsen.py --game-type 'human-computer' --difficulty 'easy' to begin a game of Schapsen.

The command-line arguments can be configured as follows:

usage: synapsen.py [-h] [-gt GAME_TYPE] [-d DIFFICULTY] [-d2 DIFFICULTY2]

This begins a game of Schnapsen.

optional arguments:
  -h, --help            show this help message and exit
  -gt GAME_TYPE, --game-type GAME_TYPE
                        The type of the players in the game.
                        Available options are:
                            - human-human
                            - human-computer
                            - computer-computer
                            - computer-human
  -d DIFFICULTY, --difficulty DIFFICULTY
                        The difficulty of the first computer player in the
                        game. Available options are:
                            - easy
                            - medium
                            - hard
                            - insane
  -d2 DIFFICULTY2, --difficulty2 DIFFICULTY2
                        The difficulty of the second computer player (optional).
                        Available options are:
                            - easy
                            - medium
                            - hard
                            - insane

Insane difficulty computer players cheat at the game — they know exactly where every card is. Accordingly, such players may intentionally lose tricks in order to pick up a better card from the talon. They may also close the talon very early on, capitalizing on the knowledge that their opponent lacks the right cards to succesfully take a trick.

Etymology

"Synapsen" means synapses in German — a happy coincidence.

Limitations

• Trading the jack of the trump suit for the face-up trump card is not yet implemented.
• Computer players do not explicitly infer the highest remaining card their opponent has in a particular suit when the talon is closed. For example, if the computer player led with the king of spades and the opponent played the queen of spades, the computer would not infer that the opponent cannot have the ten or ace of spades. Computer players do infer when their opponent has no cards left of a particular suit when the talon is closed: if the opponent responds to the king of spades with any non-spade card, the computer player understands that the opponent has no spades in hand.