[mtrpcic]

The challenge is that the level of complexity with rules interactions in MtG is absolutely enormous, especially if you want to allow the freeform format, which allows all sets and cards.

Note: You can see all the rules here: https://mtg.fandom.com/wiki/Comprehensive_Rules

[windowshopping]

Oh I didn't implement a rules engine, that would be impractical. It's a freeform platform that gives you all the tools needed to use every mechanic in the game, but it's up to you to actually follow the rules. No different from playing in person with real cards. It's sort of like a drag and drop sandbox with a lot of extra features around the edges. It's a vastly improved version of Untap.in.

[zzo38computer]

If you do not implement the actual rules, then it can probably be made to support many other kind of card games too.

However, I would be interested to have a FOSS rule engine of Magic: the Gathering, preferably written in C, and licensed by AGPL3 or some compatible license. But, unfortunately there is no official FOSS implementation; if there was (at least of the rule engine; not necessarily the UI) (especially if literate programming is used for the rule engine), I think that it would be better since the rules can be made more precise.

I would want to ensure that the rule engine has no pictures at all (you can easily download pictures separately if you want them, anyways; so the rule engine doesn't need them and shouldn't have them).