always like a rule change that mimics what a lot of DMs and players are already doing at the table.
A few weeks ago, I ran a session of my at-work playtest campaign. The characters had cleared out a nest of monsters, rescued a captured knight, and learned the location of a villain's hideout. Rather than calculate the total experience point reward for the two sessions that the action covered, I simply told everyone to level up their characters for the next session.
Informally, we know that lots of games are run the same way. Whether at conventions or online, many DMs talk about setting aside XP rewards and simply telling the players to level up after a climactic event in the campaign. It's nothing new. No particular DM invented the practice. It's just one of the many unofficial rules and mechanics that have grown out of the D&D hive mind because they work.
Tracking experience points and using them to award levels makes a lot of sense in open-ended games, where the players can go where they wish, tackle the specific challenges that appeal to them, and create their own goals as a campaign progresses. In this type of game, when the players decide to assault the lair of a blue dragon, their primary goal is most often the treasure and XP they'll gain for defeating it.
In a more story-driven campaign, however, that lair assault could have a more complex purpose. The characters might serve as an elite cadre of spies and operatives for a king. The blue dragon might be a key villain who plots against the crown. Defeating the dragon removes a threat to the realm and creates a key event in the campaign's story arc. In this type of campaign, treasure and XP take second place in the characters' goals, behind the dragon's importance in the narrative.
Both campaigns employ the same monsters, maps, and treasure, but they use them in very different ways. In the first campaign, defeating the blue dragon is its own reward, reflected by the treasure and XP earned. Sometimes that XP takes characters up a level, but sometimes it doesn't. In the second campaign, defeating the blue dragon is one step along a greater story arc. The reward lies in making the kingdom safe and completing the mission, not necessarily in collecting loot. Leveling up might feel like the best way to mark that campaign milestone, even if the XP earned by slaying the dragon doesn't quite cover it.
From the perspective of game design, the difference between these approaches becomes important when we think about how best to implement rewards in published adventures. In the past, we've always defaulted to using experience point rewards for everything. However, for narrative-driven adventures like adventure paths, that approach can prove troublesome. Designers have to jam in the "correct" number of combat encounters to make sure the PCs level up at the right pace. Adventure design thus becomes a process of matching up the right flow of XP to the correct tempo of the plot. Otherwise, if characters don't level up at the expected rate, subsequent chapters in an adventure path become too difficult or too easy.
Rather than force the issue, a much better approach is to allow designers to present both options, and let DMs decide how best to run any adventure. This simple change to an experience point mechanic that's been in place since the earliest days of D&D helps to illustrate one of our critical guiding principles in the design of D&D Next. The game must provide options to support different styles of play—especially when it's clear that the default way of doing things no longer matches the way so many DMs run their games.
Mike Mearls is the senior manager for the D&D research and design team. He led the design for 5th Edition D&D. His other credits include the Castle Ravenloft board game, Monster Manual 3 for 4th Edition, and Player’s Handbook 2 for 3rd Edition.