Highlighting stats works really well as a mechanic in Apocalypse World and it can work well in Dungeon World, but too often it doesn't, and when it doesn't, it sucks. In his post, Macklin identifies the reason as parallel intent: present in Apocalypse World and absent in Dungeon World. In Apocalypse World, all of the stats are legitimate and fairly equal ways to go achieve character goals and can all be applied in just about any type of scene. The same cannot be said for the standard D&D stat array of Dungeon World. In that game, it is almost necessary to have certain stats and stat combinations highlighted for the XP system to work properly. Strength and Con are pretty much only useful in combat. Int and Wis are excessively useful in non-combat scenes and for Wizards and Clerics respectively can be the only stat that gets rolled. If you're a wizard with Int highlighted? Cha-ching. If it's not? *Crickets*. It is possible to build a Fighter who uses Charisma extensively, but even so, it doesn't equal the XP generation capacity of the other stats. For spellcasting classes, all you need is Int or Wis, for the other classes, the optimal XP stats are one of Int and Wis and one of Str, Dex or Con depending on how one acts in combat.
Remember that the point of stat highlighting is to encourage the player to use the highlighted stat, so it is intended that you will play to your highlighted stats. In Apocalypse World there are no optimal pairs. In Dungeon World there are, and that's a problem.
So how to fix it?
Taking a cue from Apocalypse World itself, this system focuses on types of action rather than character skills. As usual, each character has two of the following highlighted (the standard method: one by the highest bond, one by the GM works fine).
This is all about stabbing & bashing! Whether it’s an orc, dragon, or your father, if someone has Attack highlighted, make sure your adventure has some fights!
If your adventure doesn’t have any fight action, disallow Attack highlighting.
Attack Moves: Hack and Slash, Volley, Magic Missile, etc.
This is all about using acrobatics and dangerous moves to survive, gain position or just show off! Whether it’s outrunning a raging inferno, traversing a living & hungry forest, or foes facing you down with arrows, if someone has Stunt highlighted, make sure your adventure has some treacherous action!
If your adventure doesn’t have any peril in it, disallow Stunt highlighting.
Stunt Moves: Defy Danger, Bend Bars/:Lift Gates, etc.
This is all about protecting others and coping with the torment you tend to take. If someone has Defend highlighted, make sure there are plenty of opportunities for them to protect others.
If there is no reason the party needs protecting, disallow Defend higlighting.
Defend Moves: Defend, Saving Throw, healing, etc.
This is all about discovering things about the immediate situation, other characters, and the world. If someone has Discover highlighted…well, frankly this is the one that doesn’t require the GM to prep extra.
If there’s no reason the party needs information, what the hell.
Discover moves: Spout Lore, Discern Realities, Speak with Dead, etc.
This is all about interacting with people to get information, get your way or understand what’s going on with people. If someone has Converse highlighted, involve plenty of intelligent NPCs (some of them people they might also fight)!
If there’s no one the party would actually interact with beyond themselves, disallow Converse highlighting.
Converse Moves: Parley, Carouse [if there was a move to read a person, that would totally be here and not in Discover]
Aid/Interfere [See Below]
This is all about helping your party (or hindering them), working with or against their actions. If someone has Aid/Interfere highlighted, don’t worry about it — they’ll cover that on their own!
This should always be allowed, except perhaps on the first session. Wait a session before putting Aid on.
Special: If you don’t want the “Interfere” part, you as a group can ditch that.
Aid/Interfere moves: Aid/Interfere
(The descriptions are adapted slightly from those on Macklin's post, mostly to combine the brief descriptions in the post itself with the more detailed explanations at the bottom of the comment thread.)
By now I've used this system several times in my fortnightly game and it works really well. Generally, the categories are self explanatory, but, there are a couple of points that should be made. The most important change is probably the decoupling of the worldbuilding moves* (Discern Teality and Spout Lore) and the spellcasting moves from the same XP source. Wizards and Clerics will still be good at both, but they will get XP for each differently. In fact, spells don't just always give XP (or not) under this system. Rather, how you use the spells determines whether you get XP or not.
The second important change is that because the categories are tied to types of action rather than specific stats, their application is fuzzy and may occasionally require the GM or the table to negotiate what a given action counts as, or if it counts in any of the categories at all, that's allowed. In particular, Stunt can be fuzzy. Because of that, I don't recommend using the alternate Bonds for XP system** which worked well enough, but was way too fuzzy. Bonds are integrated into this XP system already (Aid/Interfere category), so I now just use bonds as written.
As well as continuing to use this system in Dungeon World, I intend to using this system in my Cyber World hack, and I'm sure Colin will use it in the Geiger World hack in which it was first tested. It certainly worked for the latter; I'll have to consider whether those six types of action best reflect the Shadowrun-style of Cyberpunk caper. Comments and suggestions on that are welcome.
* I call them worldbuilding moves because, following the GM principle of Ask Questions, Leave Blanks, I like to turn these questions back to the players as much as possible and have them create the world through their answers and their actions.
** You can find that system on Story Games.
Edit: Since late 2011 we have been testing a variant on this in which we drop the Aid/Interfere XP tag. It seems to work well, but comments are welcome.