I love the Lord of the Rings LCG. We have the standard will power quest that uses willpower, we have battle that uses attack, and we have siege that uses defense…how about one more?
Endurance-This questing mechanics works much like the other quests. Players assign characters to the quest as normal, however, the total threat of the enemy is compared to the health of all assigned characters. Players do not gain threat as normal, however, any difference between the threat total and the enemy total is damage that must be assigned to each players heroes and characters. Characters can only have as much damage assigned to to as they have health preventing one character taking all the damage, and if you do not quest, you will receive a high amount of damage.
I envision this as an environmental mechanic. Think of the original quest for quest on Caradhras. Instead of question with will power, the quest will wear down the characters health. Characters will freeze to death because they die instead of giving up the will to live through will power. In addition, the monsters and encounter cards could represent smaller attacks on the players or more environmental, single event dangers.