Lanefan
Victoria Rules
To prevent exactly this I long ago ruled that you can only ever get xp once for the same opponent(s); with the exception that if you kill an opponent and then meet it again some time later (e.g. in a different adventure) after it has been revived then it counts again as if it was fresh.There's enough stories like that around I've heard it said, plus the absolute classic from Dragon magazine of that guy who killed most everyone in Oerth and wanted to know how much XP he got from the murders. But XP specifically comes from those things then leads to this thing where, yeah, first up you do the sneaky element.... But then you turn around and murder those people you just negotiated with because, that's more XP you'd be losing otherwise.
I don't give xp for treasure but they'll still strip a place bare if they can; and I've no problem with that.Every trap becomes disarm it, then tear the thing apart for more XP, sell the parts of it in town for more gold, steal the doors from the tomb of horrors type of situations.
They can have whatever in-character morals they like.Which, I mean, if you want morally corrupt vultures,
True, but there's a bunch of other corollary issues that come with any form of everyone-bumps-at-once levelling:With milestone levelling, the boosts come from completing story beats. So that gives all players an incentive to continue on with the overall things going on.
--- characters aren't rewarded for individual moments of glory or acts of bravado etc.
--- there's an incentive to let other characters take the real risks as you're gonna get the same reward anyway
--- if a character isn't present for half an adventure (e.g. it's captured, or dead, or whatever) it's in effect getting xp for not adventuring
--- a character who somehow falls behind or gets ahead in level will forever stay there
--- there's much less incentive to explore adventure sites beyond the minimum needed to complete the mission
Whaddya wanna bet that the body count would end up about the same regardless.However, XP shifts the carrot over to killing things, which could lead people to discard story.

That's up to the players as their characters. Helping the fine folk of Townsville should get the characters some xp as a goodly deed, unless they're otherwise-evil characters.Talking to people and handling fun small-end stuff isn't showering you with XP, so to those people, its a waste of time. Why help the citizens of Townsville (which can be later used as a base of operations, gain valuable allies in future efforts, and allow for storyline beats) when we can just go outside town and kill things for more XP?
Dumping a Tarrasque on a 1st-level party has nothing to do with the method of level-up other than making sure that party never has to worry about levels again.Just like how the DM picks what foes to fight, they get to decide the appropriate tasks. DMs restricting the players either way in much the same way they could just, dunk a tarrasque on a level 1 party. Its all dependant on the DM regardless. They could just as easily screw the party over in an XP only enviroment.
Indeed, but if level-up is conpletely mission-based then the strong - almost overwhelming - incentive is to do nothing beyond the bare minimum the mission demands; and a player who wants to do more is likely to meet resistance both in-character and out. It's a natural tendency to follow the path of least resistance toward achieving a goal; and mission-based level-ups only reinforce this tendency.I'd argue on the last point that they should get other treasures from doing further exploration. Sure, you get the stuff towards levelling for completing the task, but poking around further gives you more leads for future story stuff, alongside Fun Items to give more of an incentive to looking around. Not XP, sure, but its still stuff that gives an incentive to look around further. A magic item is a lot more evocative of why to explore a strange area than just a number going up that could go up from anything else.
And sure, a party could come back later and finish exploring, but will doing so get them any closer to their next level? Likely not, as the next level-up point will have been linked to a different mission.