Are there any dedicated rules/scoring libraries/frameworks/engines?

Question

Note that this is not about graphics/physics/2D/3D/etc.! Rather I'd like to know whether there are dedicated solutions available for implementing custom rules/scoring on top of an existing framework, ideally addressing most common concepts already, for example players, matches, rule variations, game selection, preferences, high scores and the like?

Or is this functionality usually included in all those graphics oriented libraries/frameworks/engines? If so, are there any that stand out in this regard and do allow reusing the rules/scoring components easily without using the graphics part of the engine for example?

Alternatively, would you consider this topic to be better addressed by a standard Business rules engine instead, as suggested in Java Rule Engine for Game AI?

Answer 1

I think you will have to write your own engine.

Have you ever looked at Zillions of Games? It's a commercial application that runs abstract games written in a script language called ZRF.

You can get some inspiration by looking at ZRF language specification. The best documentation I've found is here. Of course, you can take a look at the implementation of other games here and here.

Answer 2

I'd like to know whether there are dedicated solutions available for implementing custom rules

Yes, they're called programming languages. :)

Seriously though, to make truly custom logic, you typically need a system that allows arbitrary conditions and actions, which is pretty much what a programming language does. Or to look at it from the other direction, it would be hard to imagine a system that could encapsulate any large variety of game rules that didn't end up resembling a full programming language of some sort.

There isn't really any sort of standardisation in game rules or scoring mechanisms across games generally, so there's not much in the way of common functionality that you could meaningfully extract in this area.

Answer 3

Networking solutions sometimes include sophisticated matchmaking rule systems. I can't think of anything else.

Games have a lot of common concepts, unfortunately not all of them can be supported very well using a plugin technology or middleware. Some game engines or game tools offer prefabricated systems for making menus and highscores, but there are no general purpose solutions to implement specific screens like Preferences, Level Selection and such. These are game-specific.

Even very well documented rule systems like AD&D do not have a standard implementation. There are just too many variations possible, and each game requires its own set of rules or needs to tweak them for gameplay purposes.

Answer 4

Depending on your language, I'd write my own. The typical game's rules are generally so straight-forward (make the number of people you've killed higher than the number of people they've killed, hold this item for longer than they hold it, etc) than the maintainance of a rules engine may outweigh just hardcoding the rules.