Fantasy Grounds II (in short, Fantasy Grounds, FG, FGII, or FG2) is a virtual gaming environment for narrative role-playing games (RPGs) where players connect to the Gamemaster’s computer over the Internet or a local area network (LAN).

Fantasy Grounds is currently available for Windows (XP, Vista). Intel Macs have been succesfully used to run FG on certain virtualization software and SmiteWorks has announced that they are looking into producing a native OS X version. There are two license options, the Full and the Lite license. A Full license allows the user to take the roles of the Gamemaster or a player, the Lite license only allows the user to connect to games as a player. In practise, a Full license is also required to create or customise rulesets.

Fantasy Grounds is game system agnostic. Playing a particular game is, however, usually facilitated by the use of a dedicated ruleset, programming and graphics defining the look, feel, and functioning of the Fantasy Grounds user interface. There are a number of rulesets created by community members as well as commercial ventures.

Technically Fantasy Grounds II comprises of three major constituents: the core software, individual campaign, and the ruleset. Additionally modules can add content to the campaign or bring in "books" of reference and setting data. Extensions can modify the user interface by adding or overriding the look, feel, and functionality of the underlaying ruleset.