I am not a lawyer, but I am in law school.Every one of these claims is not worth the cost of hiring an attorney and, therefore, would likely never actually be filed except out of principal (a person that has money and is really pissed off) or Pro Se in a small-claims court._
There were two major instances where certain individuals could have sued Blizzard for reasons associated with Diablo 3. There are one to two remaining instances where Blizzard might open themselves to liability. The trigger for that cause of action has not yet occurred, but I'll discuss it anyway (#3).
(1) Pre-order cancellation denial/refusal and PvP - Breach of Contract, if it occurred.
Any individuals that purchased the pre-order of Diablo 3 expecting PvP to come with launch as promised (before news that PvP would not come with launch) and then denied a cancellation request of their order when they heard the news that PvP would not come with launch would have had grounds to sue up until the point at which they accepted the game. Upon accepting the game with the knowledge that PvP would not come with launch, the individual consented to the modified terms (that PvP would not come with launch) and thus relieved Blizzard of the obligation. The damages, however, would be limited to the cost of the pre-order. Hiring an attorney to take this lawsuit would realistically only occur if someone wanted to sue for the principal of it (or if the attorney agreed to take the case for free), because the cost of hiring the attorney will exceed the cost of the pre-order. One alternative would be to file the lawsuit Pro Se in a small-claims court, thus there is no lawyer to pay.
(2) RMAH's Early Release Lacking a Disclaimer About Item Changes and the Subsequent IAS Nerf - Breach of Contract, Conversion, Theft
The GAH and, later, the RMAH were released into the game without a disclaimer that warned players of the possibility that item properties may be changed due to balancing. Any players that purchased items with real money had a clear-cut cause of action against Blizzard for conversion of the player's property when it was altered. Further, since gold had a specified real money value at the time of the IAS nerf, ALL players who purchased gear through either the Gold Auction House or the Real Money Auction House that was subsequently detrimentally affected by the IAS nerf had a cause of action for the conversion of their property in the amount of the item's real money value (convert gold cost of purchase through the Gold Auction House to real money value at the Gold-to-Real Money exchange rate of the time) at the moment before the IAS nerf.
If Blizzard counters that some term in the EULA provided fair warning and the player accepted the term when they started playing the game, the player would likely succeed in arguing that the term was either unclear (therefore ineffective) or "boilerplate" (and therefore ineffective).The Breach of Contract is a separate cause of action that arises out of the use of the auction house and Blizzard's role in the sale as a reseller. Because Blizzard acts as the reseller in every Auction House sale, each player's contract to buy or sell an item is actually with Blizzard, not the player that is on the other end. In fact, the contract is written and stored in each player's auction house logs. This claim is susceptible to persuasive counter-argument by Blizzard because the buyer in each sale did, in fact, receive the item they purchased - it was simply changed some time afterward. This does not relieve Blizzard of liability on the Conversion claim.
The Theft cause of action is the criminal side and cannot be acted upon by players, but could have been acted upon by state or federal prosecutors.
(3) The Remaining, Not-Yet-Triggered Claim which is the reason why Blizzard cannot do a Rust Storm in Diablo 3 to get rid of duped items once the item has been traded via either Auction House and, likely, one reason that Blizzard will not remove the RMAH without glaring forewarning - Conversion
As explained during the Conversion claim discussion in part 2, because the RMAH exists as a game feature implemented by Blizzard, every item in the game that can be traded has a real money value. As soon as an item is traded via the Auction House, a record of its sale and purchase is logged and the item has a tangible value associated with it (as well as a record of the sale that is easily accessible to a player that possessed the item upon it being Rust Stormed). Upon the item being Rust Stormed, Blizzard has effectively converted the item by depriving it's possessor of their right to own and use it. Duped items that are traded for through the in-game trade window are also logged, but the records are in Blizzard's possession and Blizzard could implement a "one-day retention of records" policy regarding such records that would allow them to destroy most records relating to Duped items traded via the trading window. Thus, even with discovery, the records may be difficult, if not impossible, to retrieve. The damages for this Conversion would equal the real money value of the specific item that is Rust Stormed either at the time of Rust Storm or at the time of the last recorded trade. It's a pretty easy claim to succeed on and Blizzard would likely try to settle it through mediation (with a term of the agreement being a Confidentiality Clause).
There is a caveat to this: Blizzard can Rust Storm duped items off the original duper's account and face no liability since the duper violated the EULA in creating the item and the item has not yet been entered into the stream of commerse. As soon as the item is traded via the Auction House one time, it is, essentially, off-limits to Blizzard unless they are willing to face the possible lawsuit by the injured, EULA-complying purchaser._
As for the removal of the RMAH, this action would instantly reduce the real money value of every in-game item to $0. Off-site sale values are a violation of the EULA and, therefore, any value associated with them in such a way is invalid for Blizzard to use as evidence that an item has not been converted (except, perhaps, for players who Blizzard can prove availed themselves to breaking this EULA term - not difficult if Blizzard can retrieve records through discovery). A mass conversion on this scale would very likely see a class-action lawsuit as a response, unless Blizzard gives sufficient forewarning to all players to "cash out" if they want to.
All this being said, it is my opinion based on what I have learned and not legal advice. The rules and laws of each state are slightly (and sometimes drastically) different and could change the way each state treats these claims under their laws.
Edited by Mike#1867 on 3/31/2013 3:55 AM PDT