Endurance is a special parameter that is necessary for visiting friends. It’s shown in the top left corner of the screen when you go to their villages. Endurance is symbolized with a blue indicator with a picture of a wing. Each action while visiting an ally requires a certain amount of endurance (10 points per action). Don’t be upset if you have run out of endurance! It will recover in a ceratin period of time (1 point per 3 minutes), and you can always buy more endurance in the Resources tab at the Store.