Taking a step back from the demon hunter, there have been numerous changes to classes in general, and the current state of class design and character customization was laid out in detail. Skills are at the core of what defines a character. Fast and flashy, slow and defensive, powerful but limited, and plenty of other permutations besides. These basic concepts that can help define a character all rely on the skill system. The Diablo III skill system has gone through a few iterations during the development process, and the latest and greatest was shown off at this BlizzCon. With seven skill slots to choose from, players will be able to mix and match skills from an ever-growing pool of abilities as they level. With the inclusion of skill runes, the number of combinations is almost beyond comprehension. Almost, because we took some time, did some math, and found out that the number of skill and rune combinations available in the game reaches an astronomical number of just under 97 billion. That's purely skill and rune combinations and doesn't factor in any of the other character customization systems.

Speaking of character customization, a few new systems have now been revealed. To cut down on the number of skills and focus on just active abilities, passives have been moved out of the main skill tree. There is now a secondary tree that contains nothing but passives, which are now called traits. Traits are individual passive abilities that you can spend points in to alter core attributes and mechanics. Trait points are gained every other level, which allows even these passive abilities a way to provide an exciting and noticeable increase in power or effect. Some examples of traits were given, and both their lore and mechanics described. An example for the barbarian, Inner Rage: "While most orders teach the merits of calming the seas of the soul, the guardians of Arreat have embraced the raging inner storm." This trait can have up to five ranks. It reduces the rate of Fury lost and increases Fury gained for hitting the same target.

Some of the specifics of the trait system aren't quite complete, with a laundry list of tasks and problems left to solve. The UI for the system isn't final; a more awesome version is in the works. The idea of gaining points every other level also isn't necessarily set, and while it's the current best solution, the search continues for a better one. Right now each class also has too many traits with too many ranks, causing the same overcrowding problem that splitting traits away from active skills was attempting to alleviate. Those are issues that will be worked on, iterated, and polished as the development process continues.

Another new feature was revealed, or rather shown, for the first time: the talisman. Charms in Diablo II were items that sat in your inventory, forcing players to choose between precious storage space and character power. Most people ended up filling their inventory with charms, and only leaving enough space to pick up one or two items. That's not an ideal system in a game with such a focus on acquiring loot, so the talisman system provides an elegant replacement, setting aside a dedicated space on the character sheet to place charms and gain their effect. Rather than choosing between inventory space and useful charm effects, you'll be making decisions about which selection of charms to put on your talisman.

The skill rune system made a welcome return, as the team unveiled the latest iteration on the concept. Runes provide a powerful avenue of character customization, as they can be applied to skills to substantially alter both their mechanical effects and the visuals associated with them – one example the team showed was the witch doctor’s Plague Toads skill, which with the application of different runes morphs into a rain of toads from above or a single giant toad able to swallow demons whole. Skill runes come in five loosely themed types: crimson, indigo, obsidian, golden, and alabaster, each of which is available in seven power levels. A level-one rune applied to the wizard’s Magic Missile skill fires two missiles, while the max-level rune turns it into a screen-filling barrage.

As also announced during the opening ceremony, the player-vs.-player (PvP) portion of Diablo III has now been revealed, and is known as the battle arena. These are small gladiatorial arenas specifically designed for fast and furious PvP combat. They focus on team-based combat (balancing for 3v3), using each player's character from the single player/co-op game, with a 'best out of' format. With almost 97 billion potential skill and rune builds, and then factoring in items, the talisman system, and traits, character balance isn't likely to lend itself to an eSport, and in fact the PvP for Diablo III has always been designed a side game intended purely for fun. We know you like killing each other, so that's what it's there to provide. Even though it's not a hardcore ranked system designed to determine the best in the world, there will be matchmaking to try to get players together of similar skill, and there will be a personal progression system that will reward your character for participating in PvP.

We'll be back tomorrow with a recap of the Crafting Sanctuary panel, where the designers, artists, programmers, and writers will provide insight into what it takes to create the world of Diablo III. See you then!