Sparring duels are similar to normal duels but only take place between friends. Strangely enough, these duels are staged purely in the imagination of the two participating heroes so nobody is hurt (much) in these friendly fights and no duel records are affected making these fights very useful if a hero needs to gain some experience quickly without the risk of dropping down a few places in the pantheon. The effort needed to forge the telepathic link with another hero means that to participate, a hero must be level 7.
When the fight begins, both heroes have their health set to its maximum (based on the maximum health of the lower leveled hero) and the attacking power of both heroes is set to that of the hero with the lowest level. However during the fight, the higher leveled hero can use the encourage influence or voice commands to heal to their actual maximum health. Once the fight is over, the heroes will return to questing and their health set to whatever it was before the fight began.
To get your hero into ones of these duels, you'll need to click the "Challenge Friend" button on the Remote Control, which will then cause the hero to sit down and start transmitting telepathic signals to whichever friend you selected from the drop-down list. To do this though, you must give up 50% Godpower.
When a god initiates a spar their hero will drop everything and go into a trance while waiting for the other party to respond. This includes all forms of quests, healing at town, selling off loot, shopping, praying or fighting a monster. Like wise when the friend accepts the spar invite they will drop everything they are doing immediately. If the friend doesn't respond to the challenge within the next five minutes, the hero will gain some experience from his mental exercises anyway then go back to questing, so make sure you only challenge a friend when they are online and chatting with you via private messages or something because otherwise you've just wasted your godpower. A message will automatically show up in the private chat between the involved gods informing them that the attempt to spar has timed out.
There are 3 achievements that could be gained by sparring with firends.
Coach 1st level - Spar with 200 friends
Coach 2nd level - Spar with 50 friends
Coach 3rd level - Spar with 10 friends