I hope everyone had a great Christmas. Instead of talking about Forge's great features and its great gameplay and its great AI and its great new cards, I figured I would mention a few other trading card games (TCG) that you can play offline against the AI. Please keep in mind that none of these games are as good as Forge but they try :-)
Blue Moon is a traditional card game where you choose from one of several decks and then play against the AI. There are 8 decks that you can use and play against. The AI is very sophisticated and uses neural networks. (Download links are at the bottom of the page.)
Another traditional card game (from the same programmer) is Race for the Galaxy. Instead of having individual decks, both player draw from the same deck. (Download links are at the bottom of the page.)
While this next program isn't a card game, it has many related elements. Carcassonne is a board game where you draw a game piece and build town and roads. The rules are very simple while mastering those rules is challenging.
After you draw a random board piece you have to add it to the current map while keeping all roads and cities connected, which restricts you from adding a piece anywhere that you want to. After you place your map piece, you may put a settler on that piece. The program has a good AI and lets you play against one or more AI opponents. The programmer also lets you play against other people on the Internet and writing network code is never easy.
All three of these games are quite good and will consume many hours. Please tell me if you happen to beat the AI in any of these three games.
GTK Library (required)
Race for the Galaxy
Programmer Homepage - Also has a Mac OS X version that you can download.
JCloisterZone - requires Java
Keep on forging (my new catch phrase),