There's been a ton of talk (and flaming) over on the official D&D Forums about the new 4E system for multiclassing. Personally, I love it - but admittedly it takes a couple of brains cells to figure out how it works. In my case, it took a couple of brain cells AND a few lengthy discussions a friend of mine. Suffice it to say that 4E multiclassing is the best version ever to be written in the pages of D&D. Its just simply awesome. So, how do you do it? As I mentioned above, the effects of choosing to multiclass in 4E may seem underpowered and confusing - until you look closer.
I should first say that you should have a copy of the 4th Edition Dungeons & Dragons Player's Handbook (PHB) readily available. I do not want to have to copy/paste large sections of text from the PDF version I own and possibly violate some sort of copyright. This is the PYA part of this post. I should also suggest that you read the two page section on Multiclassing in the PHB (pages 208-209), and let it sink in. Then read it again.
I assume that your character's concept is well developed, or at least developed enough so that you have said something like "Hmmm, maybe I should have her multiclass as a...". If so, good, you are on the right track IMHO. Your character's concept should be the main motivation for you to choose to multiclass. Of course there are plenty of munchkins our there who are going to LOVE the new multiclassing, especially once it sinks in that there are power combinations that are completely unavailable to single-classed Paragon Path'ed characters.
Multiclassing can start as early as 1st level, and it is generally a good idea to do so. Thinking about whether or not you multiclass should happen early in your character's development, ideally before you even start rolling dice. This is not to say you couldn't start choosing the feats to multiclass later on, of course, but the cost deepens are your character progresses and starting later just makes the multiclasseyness progress more slowly.
So, assuming you are going to choose to multiclass at 1st or 2nd level, the first choice you have to make is to choose which class will be your '2nd Class'. This is done by choosing one of the class-specific multiclass feats on p.208 in the PHB. Each of the feats allows you to take one additional trained skill and gives you a somewhat restricted version of a class feature. The coolest thing about this feat is the following:
A character who has taken a class-specific multiclass feat counts as a member of that class for the purpose of meeting prerequisites for taking other feats and qualifying for paragon paths.The last part, about the paragon paths, makes it all worth it. You could choose to stop right there and never take another multiclass feat, but still take a paragon path from your 2nd class once you reach 11th level.
Starting at 4th level, then again at 8th and 10th levels, characters can take up to three additional power-swap feats that allow them to exchange one class power between their two classes (p.209, PHB). This is the way in which multiclass characters actually gain access to powers from their second class, while maintaining the universal limit on the number of powers available to any character at a specific level (p.29, PHB). If you choose all three of the power-swap feats, you will have the option to swap any one class power of each type (with the exception of at-will powers) between the two classes. An unanswered question I have is whether or not you can take these feats more than once (two swap two daily powers, for example). I'll have to look into this further.
Finally, the last step in multiclassing in 4E (also optional) is to choose the Multiclass Paragon path, instead of taking a class specific paragon path. The PHB briefly outlines how the multiclass paragon path works, and the benefits it bestows (p.209). At first, you might think that the multiclass paragon path is definitely weaker than choosing a class specific paragon path from one of your two classes. I think this depends on your choices, because if you look closely at the powers gained by the class-specific paragon paths versus the option to gain additional lower level powers from your second class, it is not clear that this would necessarily be a "weaker" choice. If i were to make a house rule to supplement the choice of taking the Multiclass Paragon Path, I might consider allowing characters the ability to retrain across the two classes, with any power, every time you level, as if they had access to both power lists.
In summary, 4E multiclassing is awesome! It offers a balanced, completely rethought avenue for hybrid-characters while maintaining the importance of game-balance. Multiclassing will not be something everyone will choose, but it opens up thousands of possibilities for those that do.
In my next post, I'll go more into detail about multiclassing and walk through the progression of two characters who chose to multiclass. Until then, let me know what you think?