One of the new things that seems to have taken the community by storm in the year that I've been gone is something called "gDKP" for pickup-raids (PUGs). DKP or "dragon kill points" has always been a system whereby guilds attempt to reward people with good attendance records by giving them priority for gear instead of just putting everything up for open roll. Also known as a "loot system".

The reason that loot systems are used is because when a particular piece of gear drops in a 10-person or 25-person raid, there can be anywhere from nobody to half a dozen interested parties who want that item. Some of the more common loot systems are:

Need before Greed (NBG)

• Everyone who needs the item as a sizable upgrade uses "/roll" first.
  
• If there are one ore more "need" people, then whoever gets the highest "/roll" (1-100) wins.
  
• If nobody needs, then it gets rolled off for greed.

The problem with NBG is that "need" is very subjective and often argued over. This is combined with the arbitrariness of the random number generator (RNG), so if there are three people "needing" you can easily end up with one person getting two pieces (or three!), another getting one piece, and the third person getting nothing at all for their time.

Loot Council

• When an item drops, a loot council (usually officers of the guild) decide who gets the piece.
  
• Hidden dice rolls may be involved in the case of a tie.

It's a very simple system. But it is also very prone to favoritism. People find it opaque and get easily offended.

Dragon Kill Points (DKP)

• Attendance earns you points.
  
• Different raids have different points that you'll earn for attending.
  
• Sometimes points are awarded by raid wing or raid boss taken down.
  
• You might get extra points for showing up on a "progression" night where people are still learning the fights and you will spend a lot of time dying and running back from the graveyard.
  
• Missing a raid that you signed up for, or being late without notice often results in losing points.
  
• Not following directions can lose you points depending on the guild or raid leader.
  
• When a piece of gear drops, whoever has the most DKP gets the item and spends/reduces their total DKP.
  
• There are half a dozen DKP systems. Some put static points on items, others are bidding style, some subtract the 2nd highest person's points from the winner's pool of points, etc..

There is no such thing as a perfect DKP system, but the general concept is that attendance is rewarded. The better DKP systems make sure that people spend points faster then they earn points. The upside of a DKP system if someone wants to spend their DKP, nobody can really complain about whether it's an upgrade or not.

Gold-based DKP (gDKP) or Auction

• When an item drops, people bid on it auction style.
  
• There is generally a minimum bid (usually 100g in Wrath).
  
• There may be an minimum incremental bid.
  
• At the end of the raid, the proceeds go to the guild bank (auction) or get evenly given back to raid members (gDKP).
  
• The guild or individual that organized the event may take a cut.

In some ways, this is a very good way to run a PUG raid. Even if you don't manage to win anything, you're guaranteed at least a few hundred (sometimes a few thousand) gold (money) for attending. And there's always the chance that an item will drop and nobody bids more then a few hundred gold. Usually, a 25-person Icecrown Citadel (ICC) PUG that kills 8 or so major bosses will pull in enough loot drops that everyone gets back around 2,000 gold. The richest people will end up with the loot drops, but they won't be so rich the next time around.