There has been some discussion about why the new DnD 3E rules have a scaling experience point system rather then the old school static XP system of older games, such as second edition Dungeons and Dragons or the S.P.E.C.I.A.L. system from Fallout (and its spin-offs). Since Greyhawk will be using the challenge rating system (in so far as we have been made aware) from the 3E rules, I thought a break down of what it is, as well as some common arguments on what makes it better, would be in order.

First, what is "Challenge Rating"? Challenge Rating, or CR, is a value assigned to an overall encounter faced by a group of players in the pen and paper setting. The Monster Manual and Dungeon Master (DM) guide has several guidelines for what constitutes certain CR values. By the rules, a CR is an overall challenge that would require about 20% of all player resources to complete successfully considering a 4 player party whose average level equals the CR. This 20% would be expenditure of potions, spells, scrolls, hit points, ammo, etc. As an example, let's say a DM has a group of 4 second level characters. He could put an Ogre in a dungeon room (Ogres are CR 2) and in theory, the Ogre could deal enough damage, that would require the use of a healing spell or two, and maybe the fighter drinks his potion of Barkskin as well. Now, the Ogre lay defeated, the party has used about 20% of it's resources (give or take), and the players felt challenged, maybe even a little thrilled (an Ogre can always score a very wicked critical, possibly leaving a dead player).

If the party gets lucky and drops the Ogre with one good shot, do they get full XP? Yes. They do, because the other side of the same coin applies, such as if that Ogre would have taken out the party mage with an good swing of his club, no additional XP would be rewarded. Luck isn't a factor in the CR system, in other words. On the same token, if they face a CR 12 necromancer (level 12 necromancer that would be, since with enemy characters level = CR) who summons a pack of zombies, do the players get the CR 12 XP and the XP for the zombies? No, it was the ability of the CR 12 necromancer that summoned them, they were part of the challenge he represented.

The CR system is very dynamic, as it can be molded on the fly or in advance of a party. If the party takes on the first Ogre and the DM sees it wasn't a challenge, he can quickly and easily make the next one harder, by giving it class levels (such as 1 level of fighter, or maybe 3 levels of mage, so it has access to 2nd level spells, assuming it's Intelligence score is high enough of course). This dynamics make the CR system very easy to use and a great relief for DM's who need a guideline to decide if an encounter he is preparing will destroy the players, or be a walkthrough for them. The static XP system would not do nearly as good a job letting the DM know what encounters needed to be toned down or beefed up, except with a lot of playing experience from the DM.

Greyhawk has been said to allow for the creation of 5 party members, with up to 3 (!!) more NPC's to join you as your journey progresses. That would be up to 8 party members, which is quite a large party indeed. Now, as I mentioned the CR is based on a party of 4 members. What if there are more then 4 members or less? Does the CR need to change?

Actually, the CR stays constant, and the amount of XP based on a particular CR is given by means of a chart in the Dungeon Masters guide, based on average party level. The sum value of XP is divided by the number of players in the encounter, which should make level progression pretty paced in Greyhawk with a full party, dividing everything 8 ways, unless the encounters scale with the number of party members. I also suspect strongly that we (players) will have some fantastic tactical battles on a very epic scale with 8 party members fighting hordes of orcs, mages, rogues, etc. all in one big battle!

I would also like to comment on a small difference between the way XP is handed out in Greyhawk (the core rule books) versus the refined (updated) way it is divided in the Forgotten Rules sourcebook. Under the core (release) rules, XP is handed out by average party level equally to all party members. This means, if 4 characters whose levels are say 4, 5, 5, and 3 (average party level of 4 (round all values down in DND)) defeat a Ogre (CR 2) then they all get (CR 2 with Avg. Party Level 4 = 600xp) 150xp each.

That may seem fair, but it really isn't. Mainly it's jus simple, and even elegant, but not fair. Especially considering when a character dies, he is reduced to the mid point of his previous level. Now, that could be why two party members are less then level 5 in my example. Those characters will never really catch up to the other players, in terms of level. On the other hand, the Forgotten Realms handles this much better. Under this optional rule, XP is still divided by the number of players, but the value of the XP is individualized. In my example, the level 4 character would get 150xp (level 4 vs. CR 2 is still 600/4 is 150xp). But, the level 5 characters would only get (500/4 or 125xp) and the 3rd level character would actually get (800/4 or 200xp). This means if this level 3 guy died two times, he will actually catch up fairly quickly, which in my opinion is more fun for everyone, even the DM as well as (in a video game environment) means the XP penalty can be kept and still be fun for many players (with out reloading the game because someone died, for example.) This is more work for a DM in real life, but a computer can handle these calculations quite well, and I hope the developers employ this type of XP system, even if it isn't "Greyhawk" per se.

The Static XP system works well in a Pen and Paper system still, but the scaling system that CR brings works best yet, and that goes double for a video game. With Greyhawk, if the CR system is employed, the encounters can scale much easier by assigning new creatures until the CR balances the party's average level, for example. It will be curious to see details emerge about how Greyhawk will handle XP in this manner. Many times the XP system will have to be tweaked for a video game environment, such as Neverwinter Nights (which also employed a modified CR system) giving out approx 1/10th the Monster Manual values in XP (due to the fact that you can fight a battle 10 times faster when the rules are done in the background and the combat system is graphical, such as with a computer game!). It raises the question, will this be the case for Greyhawk? Will Greyhawk reward with story experience, which is an optional rule in the Dungeon Masters Guide? Will traps and other non-creature encounters yield a CR? Will there be cases where non combat options (sneaking, diplomacy, etc.) will also yield equivalent experience to battle? These questions will hopefully be answered as more about the game of Greyhawk is revealed, in the meantime I hope this article helped new players and veterans of games like Baldur's Gate understand what the Challenge Rating system, and a scalable XP system as a whole, can provide for a game's core rules system.