Sometimes, within a game you find programmable entities. A great example are the Turtles of Computer Craft, a minecraft mod. If I had a question about programming Turtles, or anything else that's programmable, WITHIN a game, is that on topic or off topic?
This isn't one that I think will be black-and-white.
Raven Dreamer points out Minecraft Redstone, which we definitely cover. It's essentially a sort of logic gate construction setup, but betwixt construction concerns and other oddities to the system, it's the kind of thing that works here.
When you reach things that go beyond that, and into facsimiles or replicants of existing programming languages, the feasibility to go here depends a lot on the question. Basic things, especially in line with a task in-game, those would most likely remain on-topic. Going beyond that into either esoteric or extraordinarily complex things to which it's less about how to set it up in-game as it is how to get the code working in the first place, Stack Overflow is likely to be far more helpful in that department. Remember that the ultimate goal is to get a good answer for yourself - even if it's in a game and it might be on-topic here, you as an asker may be better off asking somewhere else for the more complex stuff.
Basically, don't look at it as "Is this programming?". Look instead at "What kind of programming knowledge do I need to solve my problem?" - that will answer whether it fits with us or not.
I'm inclined to say yes, it's on-topic.
Specifically for minecraft, we already handle minecraft-redstone , which is programming (though perhaps not in the way folks tend to think of it).