I just started running a game for a friend of mine and his 13 year old son. He used to play D&D as a kid and wanted to get his boy involved with the hobby, but didn't really know how. He knew I remained a gamer, so he asked me to run some D&D for him. I did... for one session. After so much math and minifig positioning and hours long fights that were the showcase of the session, but not altogether exciting (they didn't suck, but they didn't feel like they had heft), I scrapped it and introduced them to Dungeon World instead, because I'd been having such success with it in my regular gaming group.

They liked D&D, but they Loved Dungeon World, and that capital L isn't a typo. I'm much happier running this too, but I am noticing one consistent problem: they cannot shake this idea that they're fragile. Every fight in D&D left them barely alive, usually with 1 or 2 hit points. Now, in DW, they refuse to engage anything without massive amounts of backup. When there was a band of kobolds in a nearby woods, they ran at the first sound of them, and would not go back unless the town guard gave them 20 men (they already knew the kobold band numbered a dozen at the most, and yes, we' established in the fiction that kobolds were individually weak). When the captain refused, but gave them a little cash to hire people, they hired 5 NPCs to come with them, and then strongarmed a local mage guild to provide them with something better than an adept (they already had an adept).

When they did get into fights with this enhanced party, they did amazingly well. Few injuries, massive damage outlay (they rolled incredibly well). In the end, they even took down a dragon, though that hit back a lot harder and chewed them up quite a bit. And still, if they're hurt at all, they want immediate clerical healing (they still haven't grasped that the priest they hired can't heal magically, no matter how many times I say it as the character, or as the GM), and when facing any threatening situation they continually want to defer to the NPCs: How do you think we should handle this? What do you think? How do you want to handle this?

I cannot convince them that they're the heroes, they're the ones in charge of this adventuring party because there's no one else like them. I quoted right from the DW book and told them that there might be dabblers in some cities, but my one player is the only wizard (said mages from the previously mentioned guild have a very obvious limitation that my players learned about immediately; they're clearly not wizards the way my player is).

I've told them in character, I've told them out of character. I don't know what else to do. If they keep deferring to NPCs, I'm basically giving them orders all game, and I intentionally created the NPCs to be competent, but not leader types; they don't belong in charge just by dint of their personalities. Does anyone have any ideas on how to get players to stand up a little more?