It's notable that a big reason that Angband has a large number of variants is because a lot of its data is in easily readable, editable flat text files. For ins

It's notable that a big reason that Angband has a large number of variants is because a lot of its data is in easily readable, editable flat text files. For instance: https://github.com/angband/angband/blob/master/lib/gamedata/artifact.txt https://github.com/angband/angband/blob/master/lib/gamedata/... This allowed people to start work on variants without having to write C or even recompile. Also, Angband's source code has a reputation for being pretty clean and easy to understand and modify.