Exp

A player starts a new game at level 1 with 0 Exp. By collecting Exp he/she can level up.
 * A player that has collected 500 Exp in total becomes level 2.
 * A player that has collected 1.000 Exp in total becomes level 3.
 * A player that has collected ? Exp in total becomes level 4.
 * A player that has collected ? Exp in total becomes level 5.
 * A player that has collected ? Exp in total becomes level 6.
 * A player that has collected ? Exp in total becomes level 7.
 * A player that has collected ? Exp in total becomes level 8.
 * A player that has collected ? Exp in total becomes level 9.
 * A player that has collected 11,000 Exp in total becomes level 10.
 * A player that has collected 13,000 Exp in total becomes level 11.
 * A player that has collected 15,000 Exp in total becomes level 12.

Most buildings require a minimum level before a player can build those buildings.