http://versus.thewitcher.com/
You go head to head with other people. You can choose to be a Witcher, Sorceress or one of the Beast thingies.
You prepare for the battle in advance and then depending on what you choose as your battle and defense sequence, the fight plays out. I only have been in one battle which I won.

You have four basic attacks. Strong Attacks, Fast Attacks and Magical Attacks. Each can be countered by the right defense.
You can use your skill points to level up various types of attacks in these categories as well as the various defenses.
I've been leveling up Sparkle which is my fast attack. It's level 3 now (level 1 = 10 pts dmg, 2 = 13, 3 = 16 pts). If someone isn't defensing against fast attack, I'm going to do some serious damage to them.
You also have passive skills which I think might be a good way to go since you can't do anything once the fight starts. I leveled up "Power" which increases all magical attacks by 3. Considering my main attack is a Fast Attack and not magic, this might not be the best thing to level. You can gain/level Special attacks. One of these is Summon Familiar which does damage until the end of the fight.
Here is the Sorceress Skill Set:
http://versus.thewitcher.com/help/?art= ... eress&l=en
And the Sorceress quipment list:
http://versus.thewitcher.com/help/?art= ... eress&l=en
The Above link will also take you to the rest of the help/rules.
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Here's the link to my battle which I think can be viewed by anyone: (be sure to turn on the sound on the left side of the screen)
http://versus.thewitcher.com/?fight=107575458&lang=3
I'm "RanTin" in this fight.
I think the person I was fighting had less of a clue than me. His battle sequence was the same attack four times and same defense. I mixed mine up!
The strategy is in the planning as I don't think you can do anything during the fight...maybe you can. My character used my battle sequence without me doing anything so not sure.
Lots of leveling up, crap to buy with the Orens you gain from battles.


Edit:
Here's another battle for comparison and the battle prep screen:
http://versus.thewitcher.com/?fight=107575458&lang=3

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