Absolutely fantastic game, a little glitchy for mac but still amazing if you like the in depth look at history. Take any country that existed in 1399 and make essentially every political and military decision for that country all the way until the late 1800's. This is civilization on steroids.

Making an expansion for a game after the complete pack is already out is not a usual move, but this expansion is worth it. Paradox really listened to user's feedback to produce this game which adds some very powerful control features to the game and several new features that improve realism and expand your options.

Heir to the Throne is the most important expansion for EU3 as it adds a whole swath of features which make Premodern Europe seem a lot more realistic and enjoyable. A refined Casus Belli system, Holy Roman Empire improvements, and trade leagues are a few of the main improvements, but gameplay as a whole is much more effective in this edition of the game.

This expansion is beyond fantastic--it is truly necessary.

Have you ever played an expansion or a sequel to a game, then tried to go back to the original? You know how it's almost impossible to play, just because you know all of the improvements that you're missing? That's what's happened here. The new Casus Belli and Cultural Tradition systems are lightyears better than the formal system. The game also feels better and prettier. As far as this being ported to the Mac, I have not run into a single problem.

Summary: this expansion is worth it, and I haven't found any problems with the great game being ported over to the Mac.