I
n a D&D game, a player is confronted with a difficult task. What do they do? They may try to engineer a situation in which the task is less difficult, or they have advantage or something, but players generally only try this in combat or physical tasks. Most of the time, they just cross their fingers and roll the die, and see where things go from there. There just aren't many other things to do.
In a Burning Wheel game, a player is confronted with a difficult task. They immediately check their other skills to see if they have anything relevant that they can FoRK into the situation. They ask their friends for help. They consider contacting NPCs for help. They weigh the costs and benefits of spending artha on the test. They might look for a linked test, or badger the GM for advantage dice. The rules, just by existing, guide the player to immersive action, activating gears and levers all over the game world. A whole sub-plot could easily be ginned up by the player just to get a couple bonus dice to roll on an important test. In Burning Wheel, the question is always: "How bad do you want it?"
While beliefs and artha are probably the main things that make Burning Wheel the best role-playing game, I think the basic task adjudication system is sometimes overlooked in how good it is at encouraging people to engage with the world and the game itself. The second people hear about FoRKs in Burning Wheel, they're obsessed with understanding their character sheet to be able to tie in different aspects of the characters. System matters, in that it establishes the baseline for action. Seriously, guys -- there is no method in D&D for giving another player help. What the hell.
P.S.: sorry my audience of two or three people, you have to hear me talk about role-playing games again.