the expansion or final target. There can be more than one raid as several final targets may exist. Players can raid in teams of 10 or 25 ("normal" or "heroic" mode) that are assembled manually, 25 for the "looking for raid" raids, as added per MoP patch 5.4 "Siege of Orgrimmar", players in normal or heroic mode can play in 'flexible' raids, allowing teams of minimum 10 and maximum 25, which was later increased to 30 in WoD. These raids become more difficult with each added player above 10. Also in patch 5.4, a Mythic version of the current raid was added that increases the rewards and difficulty more than in heroic and requires a 20 player raid made of players all on the same realm. All WoD and Legion raids include a Mythic version. - Battlegrounds (BG) and rated BGs are small zoned instances that require players to engage a team of an equal number of the opposing faction in order to secure territory within the zone (à la "capture the flag), score resources or simply outwit the opposing team. Requires PvP to be enabled. - Arenas are small areas that require players to have PvP enabled and consist of pre-assembled teams of 2, 3 or 5 players. - Brawler's Guild is a permanent PvE version of an arena and allows players to hone their skills without requiring PvP or score ranking. They are challenging and each NPC opponent has his or her specific tactics in order of defeating an opponent or opponents. - Proving Grounds are single player scenarios that test a player's ability in either the damage, tanking or healing role. These scenarios have levels, either in Bronze, Silver, Gold or Endless mode, with each difficulty unlocked by defeating the previous one. In Warlords, a silver medal from the proving grounds is required for the desired role in order to queue for random matchmaking for a heroic dungeon. Player versus player Players may choose to fight against others in player versus player combat. World of Warcraft contains a variety of mechanisms for this. First, some servers (labeled PvP) allow player versus player combat to take place almost anywhere in the game world outside of areas for new players. In these environments, members of opposing factions can attack each other at any time. In contrast, player versus environment (PvE) servers allow a player to choose to engage in