Realm of the Titans is heavily inspired by the Warcraft III custom map, Defense of the Ancients. The gameplay is similar to DotA, wherein players battle in three lanes to accumulate experience and gold. Characters have four skills which may be upgraded after gaining experience. In addition, there is a fifth skill which is not tied to character selection or experience; it can be changed every three minutes and becomes more potent every ten. It becomes a way to either supplement a character's weakness or compliment its strength and can be switched as the game changes phase. There are 25 of these skills and may be active or passive in nature. Another unique addition is the four bosses, four huge and unique NPCs in the four corners of the map. If the enemy bosses are killed, the player's own boss will charge down the center lane in the way that a normal "creep" NPC would. As of the 14th of April 2011 there are 54 heroes in the Chinese version with new heroes added regularly. Matchmaking is done by the average rating of the players in a team, rating is calculated by wins and losses as well as personal contributions to those results. Players are put into a match fitting certain conditions such as a similar rating (depending on the number of players online), the same ISP (China only), and that the number of teams on both sides may differ by at most one (therefore a side containing one team of 5 players may only battle another team of five, a team of four plus a lone player or a team of three plus a team of two). Alpha testing began in North America on the April 7, 2011.