The Ritual Flame is a special building released for the Guild Expeditions. It can be obtained as a relic or as one of the Guild Expeditions encounter reward.
It gives a stacking 8% boost to your army's defense rating, when you are attacked. It has the same defense bonus as 2 Watchfires and also requires the same amount of space.
It is a result of InnoGames' attempt to make rewards from Guild Expeditions unique, thus replacing Watchfire as a GE reward.
Upgrade
The Ritual Flame can be upgraded by Ritual Flame Upgrade Kit item. To upgrade the Ritual Flame, use the Ritual Flame Upgrade item on the Ritual Flame that is already situated in your city. Its upgraded version will then be placed directly on the same spot in your city and the production timer will not be reset. Note that the upgraded building will be from your current era, even if the old one was from one of the earlier ages.
The upgraded version of the Ritual Flame provides 
12% defense to the defensive army.
Gallery
Old Design
