MAngband

I have been thinking of modding MAngband, redoing the monsters, artifacts, and classes, implementing features I like in PWMangband, etc. Is it simple, or are there more complicated things hidden in the MAngband code?

It really comes down to how much the mods you wish to do change the core of the game.

You can do an incredible amount of modding by simply learning the format of the various .txt files in lib/edit and then making changes there. It's a great place to start and doesn't require any c0dIng skilz.

To do the level of mods that PW has in his variant requires a good understanding of C and a lot of work with the actual coding. It's easier than building a game from scratch, but not a LOT easier. :-)