Experience points are the reward a character gets for what it does; and they (one hopes) will eventually lead to an increase in level.
The risk - and I've had this debate before in here - with levelling everyone up arbitrarily at the same time is that you may well end up rewarding characters (and it *is* a reward, you can't frame it any other way) for doing nothing.
Actually, yes. I most assuredly can frame it such that levels are not, in fact, rewards. When you go the route of ignoring XP rewards, and go for alternative rewards, levels quite explicitly become nothing more or less than a metric of the relative power level of the PCs compared to the rest of the campaign world. You are removing rewarding players with XP from the equation entirely, hence you are by definition removing leveling up as a reward entirely. Levels become a metric, not a reward; there's a significant difference.
Instead rewards are, in my campaigns at least (as I posted previously in the thread), much more tangible in terms of their impact and immersion within the game world itself.
You don't get to have a castle in the game world unless you earn it.
You don't get titles unless you earn them.
You don't get to command an army.
You won't have as many magic items (yes, you'll get a baseline of wealth with which you can purchase items, but that's it).
You won't have as many spells in your spellbook, if you are a wizard.
You won't have any favors with powerful NPCs.
You won't have a license to kill (in the literal sense) in this country.
But your level? Your raw mechanical baseline? Yeah, you're all on even footing there, because it's been entirely removed from the reward structure. Rather than worrying about what can often be a complicated balancing act of rewarding XP for killing things in combat versus fair rewards for characters who simply don't engage in nearly as much combat, you run under the baseline assumption that everyone in the campaign is engaging in activities they are gaining experience from, maturing because of.
You don't worry about rewarding XP for good diplomacy, instead someone gets a favor, a title, a trusted contact in some organization.
You don't worry about rewarding XP for successfully breaking into an evil wizard's tower without getting caught, you actually gain a tangible, physical reward no one else in the party gets, because they didn't join you in taking the risk.
You don't worry about rewarding XP in combat being by far the most common time to gain XP. Each combat will have its own rewards, or sometimes (and I know this is likely to make some shudder), a given fight will have no rewards at all. Engaging the random 1d4 griffons that happen to commonly be in the area not only didn't give you any rewards for killing animals that are part of the natural order, if you persist in such activities too much you might upset the natural order. The people that just killed a pack of alpha predators, rather than just scaring them off, likely did more damage than they might think to the local ecology. The local druid might not be too happy about that.
So yeah. Actually I can and do remove XP, and leveling, from the reward structure entirely. Levels are a yardstick measuring where the campaign currently is, and the PCs, even new PCs, are movers and shakers within the campaign world at that level.
This doesn't mean I don't understand the other approaches, and I am fine playing in games that use them. But ES@1 in particular is running under a particularly bizarre assumption: That only adventuring in an adventuring party can truly help you climb past 1st level. Because a 10th level party? Running around and adventuring? You really think yet another 1st level character is going to catch their eye at all? Or will they instead more often than not be seen as a risk, a liability. By people within the game world, that is. If it is clear that Tim the Enchanter, whose cave we just stumbled upon, is barely above an apprentice in power, that group of hardened adventurers isn't bloody well likely to accept his company, no matter how pleasant it might be. Because with the kinds of experienced villains that party fights regularly, Tim will easily be cut down with a single swipe of a sword by even the lowliest of the bodyguards of the BBEG.
That druid you just stumbled upon, who has been guarding these lands for decades and has been given leave by the local spirits to go deal with a grave threat, is only 1st level because this is her first outing with your adventuring group.
The grizzled vet of three wars, a sergeant at arms who has trained countless whelps, seen more young soldiers die in campaigns than he can count, is 1st level because he hasn't adventured with your party.
Having every new PC come in as a novice, just starting out in the world for the first time, effectively eliminates a huge number of potential backgrounds for why someone would be joining your high-level group of adventurers. Drizzt is joining up with your party of 11th level characters on a dire mission to save the North? Well, he's just a 1st level ranger, fresh from Menzoberranzan. Raistlin is joining your party, having already earned his red robes, and the title Wizard of High Sorcery? He's 1st level, even though the rest of the group is 15th level and in the midst of a massive campaign against armies of evil dragonriders...because.
It just ends up causing a pretty significant disconnect, because young, inexperienced characters wouldn't likely be WELCOMED into a seasoned party. Not unless they are extraordinary, and even those would be the exception that prove the rule. One? Maybe two such characters coming in at so low a level in a mid-to-high level campaign? Sure, ok, perhaps. But all of them? Not without eliminating an enormous percentage of potential back stories, or making those backstories not mesh with the relative power level of the character itself. Sure, your druid has been protecting these lands for decades, but she only knows a handful of the weakest of spells in a druid's repertoire, deal with it. That...is a bit too draconian, too heavy-handed a rule to impose, imho.
