| Vassal Engine | |
|---|---|
 | |
| Developer | The Vassal Team. |
| Initial release | 1996 (1996) |
| Stable release | 3.7.18 / September 23, 2025 (2025-09-23) |
| Repository | |
| Written in | Java |
| Operating system | Any |
| Platform | Cross-platform |
| Available in | Multilingual (English and 6 other languages) |
| Type | Game engine |
| License | GNU LGPLv2+ |
| Website | vassalengine.org |
TheVassal Engine is agame engine for building and playing online adaptations ofboard games,tabletop games andcard games. It allows users to play in real time over a live Internet connection, and also by email (PbeM). It runs on all platforms, and isfree,open-source software.[1][2] For example, there is aStar Wars Miniatures module, where players can play with up to three others in a digital replica of thetable-top game.
It is written inJava and the source code is available fromGitHub under theLGPLopen source license.[3]
Vassal began as an application for playingAdvanced Squad Leader. This program was named VASL, an acronym for "Virtual Advanced Squad Leader." In 2002, this was expanded into a generic board game engine now called Vassal, with VASL being changed into just one out of many modules for Vassal.[4][5]
Vassal modules exist for over 1000 games.[6]
In September 2008,Games Workshop issued a cease-and-desist order regarding the Vassal module for Warhammer 40K to Tim Davis, its maintainer at that time.[7] The module is still played.
Games Workshop has also issued a cease-and-desist order regardingSpace Hulk[citation needed].
Similar engines for making board games include ZunTzu[8] and Boardgame.io.[9]
