To initiate a challenge you must first have successfully played at least one Mission in the game. After that, you can arm your hero with different weapons, armors, and items, and challenge other players. When you first start playing, the choice of weapons is often suggested by personal taste, then eventually you will learn (through the lessons on strategy and experience) the best combinations to highlight your hero for a greater rate of success and survival. It's worth noting that a big support can come from clans, if you decide to join one or start a new one, yourself. The clans are groups of players joined in a common ideal. People belonging to a clan are recognized by a clan tag (up to 4 characters) which appears before their nickname. All components of a clan can use, among other things, a private chatroom within the game, which allows them to develop strategies and communicate quickly with all their fellow clanmates. In the main menu of the game you will find the entry 'Board', which contains all recruitment messages posted by Clan Chiefs. Referring to the board is a good way to know which clans are looking for new members, in case you're interested in becoming a part of one.