Demon Doors - Fable 3
Demon doors are already shown in the map of the area they're in so you can just fast travel to their locations should you want to complete their tasks.
Requirement: Use expressions on another hero.
Reward: Legendary Weapon
You can do this with a friend through Live or do this offline with another character stored locally, preferably on another profile. You need to use all the available (and unique) expressions until the door acknowledges the task completion.
Mistpeak Valley Demon Door
Requirement: Be Albion's ruler
Reward: 1,000,000 Gold
After your coronation, just talk to the door and grab the loot behind it.
Sunset House Demon Door
Requirement: Bring an innocent child with you (biological or adopted)
Reward: 25 GS, 3 Summon Creature Potion
You need to bring a child with you, either adopted or biological. Take note that the child's status must be at least 'Fine'. If he/she's unhappy, you need to improve your relationship by using positive gestures and giving him/her the gift that he/she wanted. The door will automatically recognize the child once you met to fulfillment.
If you want to get the reward from this door immediately, you can just get it on with the opposite sex and create your own little horror. Otherwise, if you prefer adopted kids, you may want to wait until later in the game until the orphanage in Bowerstone Industrial opens.
Just bring the kid to the door and watch it get emotional. Wait for it to finish the drama until the door opens. Once inside the other side of the door, just ignore the main tavern where there are several merry skeletons prancing around. Take the stairs on the side of the tavern and find the chest in the room in the second second floor.
Requirements: Wear ugly clothes (pyjamas), have full weight gauge (check Hero Stat in the Sanctuary)
Reward: 40 GS
First appear to the door using pyjamas. If the door doesn't seem to approve of it, get hold of the pyjama set of the opposite sex. The door will then tell you to 'eat like a pig' and gain weight. You need to have a full weight bar in your Hero Status screen before the door recognizes you. To increase weight, you need to hog down all high-fat foods you can find. It seems consuming large amounts of liquor, fish and pies will rapidly increase your weight. Once the conditions are met, talk to the door once more to gain access to the reward behind it.
Should you wish to lose the weight you gained for the sake of this quest, consume a large amount of low fat foods such as fruits and vegetables.
Requirement: Full Good or Bad Moral Gauge.
Reward: Legendary Weapon
You need to either be pure good or pure evil. (Your morality meter is either in the farthest left or farthest right. The door will open automatically if you met any of these requirements. The reward will still be the same regardless of your moral standing.
Requirement: Fully maxed out weapon
Reward: Military garment set, Summon Creatures Potion
Check your weapons and use the one that will fit your fighting style and moral standing. That way, you can easily meet its requirements. Fully upgrade it then show it to the door to open it.
Mourningwood Demon Door