The plot of Barbarossa is based on the legendary adventure of the Barbarossa pirate brothers (Αruj, Ilyas and Khizr). ​ Returning from a trading voyage to Tripoli, the boat of Aruj and Ilyas was stopped and plundered by a galley from Rhodes Island, operated by the Knights of St. John. The Christians killed Ilyas and kept Aruj as a prisoner, until his family could arrange the payment of a ransom to release him.In Barbarossa we build upon the above story to create a series of fictional scenarios in order to substantiate the game roles required to support the different game modes. Barbarossa consists of two phases. 

Phase I of Barbarossa is called "The Conqueror". The motivation behind the first game phase’s design is to raise the level of game awareness of participating players; namely, to familiarize them with the use of mobile/pervasive technologies, deepen their understanding on the overall game scenario and augment their physical, cognitive and emotional immersion. ​Along this line, we have chosen to design "Barbarossa The Conqueror", an invitational game mode, which comprises the first phase of Barbarossa. This game mode is available to the public aiming at raising game awareness.

The players proved to be most effective in completing the Conqueror scenario are the ones that will be invited to continue to the second phase of the game. To make it easier for potential players to actually play the Conqueror, the latter will be freely available by Google Play so that the ones interested would be able to download it and play it on their own Android devices.Having completed the first phase of Barbarossa, selected players are contacted to continue on the second phase. In particular, the most effective Conqueror players are invited to act as Treasure Hunters and allowed to invite individuals of their choice to act the Knight. The player that will act as the Pirate will be chosen by the developer team.

Phase II of Barbarossa is called "The Interplay". Our second phase game scenario involves a modern Treasure Hunter who discovers (within an old book) some information about a chest filled by the three Barbarossa brothers with their most valuable treasures somewhere around the city of Mytilene in Lesvos (Greece). In the first phase there are two different leagues of players, those who play near and into the city of Mytilene and those who do not. In order to open the chest the Treasure Hunter (the first player in the league of the players that play inside or near the city of Mytilene) has to cooperate with two more players, a Pirate who is chosen by the Treasure Hunter to help him, and a Knight (the first player in the league of players that play outside the city of Mytilene). The player who acts the Treasure Hunter has to locate the real chest in the city of Mytilene which is locked with 2 combination locks. The Knight and Pirate players follow and complete an individual sub scenario each that rewards each one of them with one of the locks combinations. Having the real chest and the combinations of the locks the team can unlock the chest and follow the instructions inside it to participate to the prize lottery.