Geek and Sundry recently released a brief article about rules to steal from other systems to improve your D&D game. (Here is a link to the full article http://geekandsundry.com/steal-these-rpg-mechanics-to-make-your-dd-game-better/ )

The one that stuck out to me the most is this.

SUCCESS AT A COST

The question at the center of Fate Core is simple but challenging; what are you willing to pay to succeed? Fate players usually spend Fate points and invoke aspects to pay that cost, but there is always the option to succeed. Why? The game offers success at a cost as an option if the player comes up short. Players that choose to succeed at a cost negotiate with the Game Master what they have to give up to succeed. Everything is on the table and the player is always able to walk away if the price is too high. But, sometimes, after an epic lead-up and a less-than-epic roll, adding a little negotiation to the control of the narrative can bring the story to a more satisfying conclusion.

The trick to making this rule work in Dungeons and Dragons is to gauge the cost of success versus what the player might be willing to pay. Delivering a critical blow to a hated villain might be worth the cost of a beloved magical item breaking. Picking the lock to the dragon’s vault might be worth the cost of being haunted by the master thief who failed 200 years ago. Dungeon Masters will be surprised what sorts of trouble players will agree to in exchange for a sure thing. And if the teams can’t come to a deal, failure still stands as an interesting option.

Now I really like this idea for my Curse of Strahd games. When we started I had the players roll for 7 ability scores, the 7th being sanity. I'm debating about tying this into Sanity.

What do you all think of this idea? Any thoughts on how to introduce this without really messing with the balance of the game?