When you have a unified XP chart, you are saying, "all class' power levels are roughly equivalent!" A level 5 thief should be as powerful as a level 5 fighter or level 5 mage.
Back in the original D&D, the designers knew about the power imbalance of mages and fighters (2,500 and 2,000 xp base), and put them above clerics and thieves (1,500 and 1,200 xp base). The charts were never a linear scale, just because a mage needed 2,500 xp for level two did not mean they advanced twice as slow as a thief all the way up, the difference between thieves and mages was never really more than a level or so of lag behind for the mage (a 14th level thief and a 12th level mage had around the same total xp).
Still, there was a difference.
In 3rd edition, we got the unified XP chart for all classes (and the CR system), and every class advanced at the same rate. Not surprisingly, those pesky power level differences came up, and this triggered an endless balance and rebalance cycle for all editions of the game since. You even see this in Pathfinder Unchained, where they redo three of the classes to make them compare better with the entire set of classes in the game.
"Mages are still the most powerful class in the game!"
"Rogues are weak."
"Why class X why you get all that plus a better to-hit with class Y?"
You hear a lot of this because naturally, a player expects a level five class X should be an equal and balanced choice with a level five class Y. You end up having to do the power and math shuffle on every class, again and again, like D&D 4th Edition's endless and painful errata and changes to classes and items.
If there was a problem with relative power level balance in the old "per class" XP chart system the issue could be easily addressed by just adjusting the charts. Mages still too powerful? Push them out by a thousand points here or there. So a level 9 thief is equivalent in raw power level to a what, a level 6 mage? Okay, that's where the charts should go.
We don't need to balance the class, we just adjust the charts.
The CR System SolutionPower levels were 'evened out' because of the CR system, really, and also to simplify things to avoid having a lot of charts. But note that in old school D&D, you did not all need to be the same level to adventure together, and conceivably, that level 6 mage in a party full of level 9 characters could and will contribute. This "the party needs to be within one level of each other, two max" sort of thing feels like it comes from MMOs and computer games, where it is important to balance things with math to make sure "everyone has a good time."
In the original D&D game, how did you determine CR? Here's how you did it:
"Last time our party of level one characters fought an ogre we got out butts kicked. Let's not do that."
You learned the game. There weren't thousands of creatures so you could weigh difficulty for them all relative to classes and powers. You failed, failed some more, died a lot, and then discovered what worked. You got lucky, and knew how far you could push your luck given what level you were and who was in the party. You had to think.
Try-fail-adjust-learn-succeed? That sounds like what you do in any game when you learn it.
The problem I have with CR encounter balancing is it assumes the dungeon master is a computer that balances content to entertain the players. The DM is there to "entertain" people like a DVD player, put in the disc, do the math, balance the game, and run the script. Press play.
Saying, "nobody likes getting killed," in D&D is like saying "nobody likes losing in Monopoly," and coming up with rules so one loses. Or even behind on money or properties every turn because every player needs to feel relative balance with each other. Yes, Monopoly is a competitive game, and D&D is cooperative, but if you take the learning curve out you take out the part of the game where becoming an experienced player is knowing what a monster does what and how you can fight them at what power level.
Pen-and-Paper as VideogamesSomehow I feel this is part of the progression of D&D towards an entirely story-based game instead of a board game. CR does what? Balances encounters so you can get through them all as a party so you can complete a story at the end of the night. Without CR, you run around the ogre's room in the center of the dungeon defeating rats and spiders while looting what you can, and maybe you never fight the ogre - and you decided if you 'won' based on survival. If there was a goal, it had nothing to do with 'story award xp bonuses' or a series of balanced encounters leading up towards it. If you got the chalice, you got it, and you earned the king's trust - xp and balancing had nothing to do with it.
Then again, the king's trust is a very nice thing to have, and you don't need to put an xp reward on that either.
Healing surges, regenerating resources, encounter powers, and anything that resets the party's power is another step towards a story based game (and also an admission of the inability to balance a resource depletion game, like the classic D&D model of play). You have to "reset" the party for the next "encounter" because you can't balance things in the overall scheme, when really, what resources the player have and want to spend should be up to them. It feels fake, like an MMO where health and mana regenerate before you get to the next room, and the entire game is designed to be low-risk entertainment rather than a challenge of how to spend limited resources dwindling all the time.
Don't get me started on this "go back to town" sort of "one encounter per day" cliche either, That comes from videogames and it assumes the world never changes between visits to the dungeon. The pen-and-paper game as videogame mentality breeds this unrealistic way of thinking.
Less is More is FunSometimes we like games to be smaller in focus with a limited set of content, such as Pathfinder Basic Set, where we can get the feeling of how monster X relates to class Y and power Z. Part of why we love Labyrinth Lord and Basic Fantasy are because these rules are complete, done, and what's in the game is what is it. You can learn them. You know a level X thief is about as powerful as a level Y mage. You know how to defeat an owlbear, and how much power and resources that will take.
When you have thousands never-ending of monsters, feats, spells, classes, and powers, you never get a feeling of system mastery. You are always being hit with a new something, reacting, and never knowing how your power relates to the others before it is replaced and you move onto the next one. In Basic D&D, the fireball is what it is, and it is a unique AoE spell that fits a unique role. We don't have or need seventy variations of the spell. It is a unique puzzle piece to be pulled out when you need a...fireball.
And it becomes a unique resource we can spend, that does not recharge between fights.
That "how many resources it will take" is key. This is what the original D&D was about in the macro for the entire play session, not the micro between encounters. You should be able to run out of resources and 'fail' to achieve your goal, due to luck, normal use, or carelessness. You should decide if you will come back another day, if that is possible, and the next time the dungeon should change (tougher, better defenses, less loot, the chalice is lost, or they clear out) when the party gets back.
Know Your GameThere is a distinct game design here when you realize what is going on, and how every piece works together. Imposing systems like CR and auto-regen resources on what was a limited-resource game throws everything out of whack, and D&D becomes a totally different game. We are seeing a shift from resource management to story based gaming, while still thinking we are managing resources.
If you want a videogame style RPG, that is cool. Know what these look like. If you want a resource-based RPG, know what those look like. If you want to make a pen-and-paper game play more like a videogame, it is helpful to know what you need to do to get that result. If your love is resource-based play, know what rules enhance that experience and play that way.
We live in a time where every publisher tries to make every game appeal to everybody, and it all blurs together. The influence of MMOs and computer games in pen-and-paper gaming is strong, you see a lot of these videogame-inspired concepts in today's games, and they often conflict with how the original game was designed.