I'm not quite sure why the comparison is being made here at all. Go has an incredibly simple rule set and is a game played with perfect information. That such d

I'm not quite sure why the comparison is being made here at all. Go has an incredibly simple rule set and is a game played with perfect information. That such deep complexity emerges from those things is part of what makes the game so beautiful. In Magic, randomness and limited information are integral elements of the game, as are the myriad rules and their interactions. That "so many rules have been piled on over time" is not some sort of accident; it's been the intention from the beginning and it's a huge part of what makes the game fun. It's simply a completely different beast from a game like Go. Labeling one game's complexity "artificial" in some arbitrary manner is not meaningful. What's rather clear is that creating a rigorous mathematical model of Go is fairly straightforward, while doing the same for Magic would seem to be a few orders of magnitude more complex. (Also, that a creature's power and toughness might change has been part of the game since the very beginning: see Giant Growth.)