Are they the same? What do they mean? 
How many times do I hear this question?

Enough. Enough to get me to write this little bit about it. I mean, the Rede and the Law of Return are a part of what Wicca is all about, after all. 

Ok, we'll start by looking at the ideal of the Rede. You can read one version of the Rede by clicking here. 

As much as some would like to think the "An' it harm none, do as you will" statement is a Wiccan ideal, it really isn't. After a little extra research, I've found that EVERY religion has a tenet like this somewhere - most of the hospitals I've been in have a poster (Pagans aren't on it, but what can ya do?) stating the general idea in each belief system. I hunted about and found a page that lists most of them (which you can read here). We've all got our ways of saying it. The Wiccan idea is that you are free to do as you will so long as your actions shall cause no harm to yourself or other living things. Makes sense. Now this doesn't mean you should stand idly by while someone beats the crap out of you. This causes harm to yourself, and you've every right to stop it. If that means kicking your attacker in the groin, so be it. The Rede isn't meant to turn us into spineless pacifists; it's just meant to teach us that things like picking fights, sport hunting, or killing sprees probably aren't very nice things to do. This of course also ties into my next topics.

The Law of Return (featured here) is similar to both the Rede and Karma, and yet stands alone. The idea here is sort of like Newton's Third Law. For everything you do, there will be repercussions. Now it may not be entirely obvious every time, but even in little ways, this always comes into effect. If you drink all the juice on Monday, there will be no juice left for you on Tuesday. If you spend your money frivolously on the weekend, you won't be able to buy something of importance by midweek. If you punch someone in the face, they'll likely punch you back. Whether big or small, the Law of Return permeates our entire life.

Karma reaches much further when it comes to repercussions. Most Pagans and New-Agers in general usually use this when describing the Law of Return. Well, it'd be pretty silly to have two forces acting on your life, wouldn't it? No. Karma reaches further forward and back. Essentially, whatever you do in this life is setting up the situation for your next life. As well, your past lives have laid the groundwork for where you end up in this life. Now you might be saying "I don't remember my past lives, so how can I be paying for them now?" Well you may not remember (and I say MAY, because some people have done regressions and whatnot), but your soul holds onto everything.

So go forth, live your life, but keep these three things in mind. While Karma may not be a part of Wicca's core, the Rede and Law of Return most definitely are.