My original tutorial for setting up Mecanim animations in ORK proved to be quite popular. But it's almost three years old now, and... to be honest, I was still relatively new to Unity development and I didn't get everything right the first time around. I have learned so much about Mecanim during that time that I need to do a complete rewrite, rather than simply updating my original tutorial.
So this is the long-awaited, comprehensive guide to setting up Mecanim animations for ORK. Unlike the previous tutorial, I'm going to start with the basics. This isn't going to be a beginner's guide to Mecanim, but I am going to cover some topics that some readers might find overly basic. Please bear with me; I will get to the more advanced stuff in due time.
I will be structuring this tutorial in more of a step-by-step flow than I did in my original. I will be using free animations which you can download from Mixamo if you wish to follow along. I will be using their "Y Bot" character model for downloading the animations, as it is a good neutral model to use. If you have a specific model that you want to use instead, you can upload the model to Mixamo before downloading the animations. This will help with retargeting the animations to fit your character model's rig. So anytime I mention the Y-Bot just substitute your own character model; for the purpose of this tutorial, I am simply going to assume the use of the Y-Bot.
One nice thing about using the free Mixamo animations is that they aren't completely set up for Unity when you download them, so in preparing them for use, you finally get to understand all of that stuff about baking Root Motion into the pose and all that. ;-)
The content of this tutorial is applicable to both turn-based and real-time games, but it is somewhat tailored to turn-based games or real-time games with an indirect control scheme (i.e. click-to-move such as in Baldur's Gate). For real-time games with a direct control scheme (such as Skyrim, Gothic, Zelda, etc), I find that an advanced character controller asset is better suited, as they can provide more fluid and responsive controls.