So what has changed? Only two things:
1. Anti-towing code. People have been worried that they need to count up everyone’s levels when they join a party and try to figure out their average party level, as if things had changed from before. The truth is, we’ve been running anti-towing code for almost two years, and no one seemed bothered by it until all of the recent talk about CRs and party levels and such

Another truth, something I can now tell you but couldn’t before: in the second batch of changes, we took out the anti-towing code. Why? Because you were worried that guilds and other groups with a wide spectrum of levels would not be able to make xp (even though we knew that this was never an issue before, since no one’s brought it up in the past two years). So we decided to test it out. What was the result? People started towing again

So we have added some new anti-towing code that is a bit different from the old. In the old system, the highest-level party member was always counted thrice, which worked to jack up the average party level. While this made it somewhat difficult for epics to tow newbies, it hosed everybody across the board. The new system calculates your party level and then compares it with a minimum party level. This minimum party level is seven less than the highest level party member's level. If your average party level is less than this minimum, the party level is set to the minimum and xp is calculated accordingly.
Some examples:
Old system - a lvl10 and a lvl1 party up. The avg. party level is (10 + 10 + 10 +1)/4 = 7.
New system - for the same party, the avg lvl is (10+1)/2 = 5. The minimum avg. party lvl is 10-7 = 3. Since 5 is above the minimum, the avg. party lvl stays at 5.
Old system - a lvl30 PC parties up with a lvl1. The avg. party lvl is (30 + 30 + 30 + 1)/4 = 22. Another newb joins the party, lowering the avg. party level to 92/5=18. If another newb joins, the party lvl lowers further, to 93/6=15. This party can now get at least minimum xp for creatures of CR8 or better, with the epic PC killing the creatures easily while the newbies hang back and watch.
New system - a lvl30 PC parties up with a lvl1. The avg. party level is calculated at (30 + 1)/2 = 15, but the minimum avg. party level is 30-7=23. So the party level is set at 23. No matter now many more newbies join, the party level will remain at 23. This party will get token xp (1d2) if they kill creatures of CR10 to 15, and at least minimum xp (1d4+1) for killing creatures of CR16 and above.
Note the result: newbies and lowbies no longer get affected by the towing code. Epics simply can't tow to lower their party level to exploitable levels, but can still lower their party level to within reason, considering their immense power.
2. Associates are now counted when calculating avg. party level. An associate is defined as any creature under a PC’s control - familiars, summoned creatures, animal companions, and creatures dominated by spell, psionic power, or animal empathy. So if a mage solos a creature he will get some xp, and if he summons a creature to aid him he’ll also get xp. This includes the Gate spell - yes, you will get xp for using Gate summons now. If you fight things below your CR you probably won’t see much of a change in xp, but if you and your associates kill things equal to or above your CR, you will notice you gain more xp solo compared to with a party of associates in tow, because they are taking their cut of xp for helping you defeat things.
To make things clearer, all associates are counted just like PCs. If you are solo, you are a party of one. If you summon a familiar, you are a party of two, and will get the party bonus for xp, but your xp is now split evenly between you and your familiar. If in addition you Gate in a balor, you are a party of three, and the xp is split three ways.
To prevent exploitation, if an associate has less hit dice than its master, when avg. party level is calculated its master’s hit dice are counted for the calculation. Some examples:
A lvl1 mage summons a dire badger (3HD). Since the dire badger’s hit dice are higher than its master, its own HD are counted and the avg. party level is (1+3)/2=2.
A lvl30 cleric summons a dire badger. Since the dire badger’s hit dice are less than its master’s, its master’s HD are counted and the avg. party level is (30 + 30)/2 = 30. This prevents people from summoning wussy creatures and then telling them to stand back while they go off to fight, taking advantage of the reduced party lvl to gain more xp.
Note that the anti-tow code works hand in hand with this. If a lvl20 mage summons a 40HD balor, the avg. party lvl is calculated initially as (20+40)/2 = 30, BUT the 40HD balor is the highest-lvl party member, so the party level is adjusted to 40-7=33. In essence, this means that if you use a spell or psionics to gate in an uber creature, you’ll get xp for having it kick ass for you, but you’ll probably only get the token xp (1d2) unless you find some creatures with really high CR for it to kill.
I repeat, these changes are only live on the Wilderness as of this posting. Feel free to go check them out and post your feedback, both positive and negative, here.
Lastly, a word about epics, something that has been said in the past but not said recently, though it should be. Avlis doesn't cater to epic levels. Never has, never will. If 99% of the PCs are epic, we still won't change how things are done. That doesn't mean we actively try to punish epic PCs, it simply means that the play experience is focused mainly on "The Grind," the progression from level 1 to level 20.
The 3E xp progression is linear, but Avlis' is not. Your progression tapers off once you hit the 20s, and once you hit the 30s you pretty much hit a wall, simply for the fact that there are very few challenging creatures for you to fight, nothing close enough to your level to give you a lot of xp. Avlis is built that way on purpose. Think of it as a pyrimidal structure - if there are billions of commoners, then there are perhaps millions of 3rd lvl soldiers, hundreds of thousands of 5th lvl lycanthropes, etc., until you get to the top, where there are only a handful of kings, lords, heroes, dragons, etc. There should NOT be millions of dragons for epics to hunt.
When half the PCs are epic, epic isn't epic anymore. We have already reached that stage; epic lost its epicness long ago, sadly. It shouldn't be easy to reach lvl30, and yet by the old system I could have done that with Gram this year, and he's lvl10 right now. There should only be a handful of people in the world who can singlehandledly beat back armies of men or hordes of demon lords, and yet every night you can run into a dozen such people at Elf Gate. Part of that is simply the age of our PW and the ability we've had to retain some long-term players, but part of it was a system that allowed you to reach epic levels, and continue to advance in them, rather quickly.
Getting to and advancing in epic levels should be as tough as it is to get to the higher echelons of crafting. Not everyone should be able to do it. People who have done it should be proud of the achievement.
The xp changes were never meant to hurt epics, but neither were they meant to help them.