This is a quick overview, so I'm going to ignore off-spec loot for simplicity's sake.
Shroud is a loosely-coupled DKP system. Earning DKP is pretty standard. Points are awarded for whatever the guild thinks is appropriate. Runycat's guild primarily awards points for Time Spent Raiding, but you could easily award points for Boss Kills or whatever other metric you deem appropriate.
Spending DKP is where the system gets interesting. When an item is up for distribution, a raider may choose to "shroud". Of the raiders who shroud, the one with the highest DKP gets the item and loses half her DKP. If no raiders choose to shroud, interested raiders can roll for the item. The raider with the highest roll gets the item and pays a standard fixed minimum fee.
Here's a quick example: Coriel has 500 DKP and Kent has 600 DKP. If an item drops and both raiders shroud, Kent would win and pay 300 DKP. If only Coriel shrouds, she wins the item and pays 250 DKP. If neither raider shrouds, both /random. Coriel rolls a 84 and Kent rolls 22. Coriel wins and pays 10 DKP for the item. If Kent had rolled higher, he would have paid 10 DKP for the item.
The main insight of Shroud is that there are three values of loot:
- Sexy loot - this is loot that is greatly desired. For example, Tier sets and Best-in-Slot weapons.
- Everyday upgrades - these are items which are upgrades, but which a raider doesn't get excited about. She''ll take it to keep it from being disenchanted, but isn't really going to care if another raider gets it instead. The majority of loot in the instance falls into this category.
- Unwanted items - these are items the raider doesn't want at all.
Is this valuation correct? My experiences lead me to believe that it is correct. My guild runs a pure English Bid Auction system. This is the system used by traditional auctions with multiple rounds of bidding and a fast-speaking auctioneer. Not the fastest system in the world, but items end up being sold at their true value at that point in time. What I've noticed is that loot either goes for hundreds of points or it goes for near-minimum. There's not a lot of in-between. As well, it's very few pieces--primarily Tier sets, BiS weapons, and amazing trinkets--that have the sky-high prices.
Shroud handles each of these categories of loot in a different fashion. Sexy loot is distributed in strict accordance with the point system. The person who wins that loot has the most points, end of story. Meanwhile, everyday upgrades are distributed randomly, with minimum points spent.
Shroud has all the advantages of a traditional DKP system when it comes to the highly-prized loot. You won't get the case where someone who raids a couple days a month beats a 100% attendance raider on a Best-in-Slot weapon. That type of situation is what causes high-attendance raiders to seek out a new guild.
However, raiders of all attendance levels have equal shot at the everyday loot, which comprise the majority of the epics in an instance. This gives your more casual members a good shot at getting some loot, rather than having all of it monopolized by the high-attendance raiders.
Shroud also avoids the disadvantages of a system like Spend-All DKP or Suicide Kings in that a raider can still obtain smaller upgrades while saving for a prized item. Loot that can be used should never end up sharded with this system.
Shroud also allows raiders to determine what loot is really valuable and what is not. The choice to shroud or not remains with the raider, not the officers.
Finally, since shrouding costs 50% of your DKP, hoarding of points is discouraged and people are brought back to the rest of the group fairly quickly. There are no worries about inflation in this system.
The biggest disadvantage is that the system is complex and that makes handing out loot more time-consuming. You first have to see if anyone wants to shroud. If no one does, then everyone who wants the item must roll, and you need to see who has the highest roll. The amount of complexity is probably unnecessary for a guild where the raiders have similar attendance patterns. A single-bid or fixed-cost DKP system would probably be faster and just as accurate.
The complexity increases even further when you consider off-spec loot. Should you let someone shroud on off-spec loot? Maybe, maybe not. Even without that, off-spec loot would add another round of waiting to the process.
Shroud also has the overhead and record-keeping of all DKP systems, as you have to track points as they are earned and spent.
The final disadvantage that I can see is that a raider might attempt to game the system, choosing not to shroud and betting that no one else wants to roll on the item. Then she gets upset when someone with much lower DKP wins the roll over her. While it is her fault for not shrouding, drama is rarely rational. Indeed, sometimes people get more upset when they are the ones at fault.
Shroud is a decent loot system for a guild with a core of high-attendance raiders filled out with a number of more casual players. It gives both types of players a shot at rewards, ensuring that neither side is treated unfairly. It avoids several pitfalls of other systems--like Suicide Kings, Pure Random, or Pure DKP--that are traditionally used by this segment of guilds.
However, the price that is paid is increased complexity. And you have to wonder if this complexity is really necessary. Shroud is really close to Pure Random, and Pure Random is so much easier to deal with. The real question a guild should ask is how likely is the situation where a low-attendance raider beats a high-attendance raider? How much will the guild care if that happens?
If the guild can handle that situation happening without drama, I think Shroud becomes unnecessary, and Pure Random becomes the system of choice. But not many guilds can actually handle that. And for a more casual guild, losing a raider who is part of the backbone of your raid team can be much more devastating to your ability to raid than losing someone is for a traditional raiding guild.