Hated
Players who are hated will, in most cases, be attacked on sight. In some cases, such as sanctuaries, the player will not be attacked, but will not be served or spoken to by an NPC. Guards who hate a player will not help the player, and can be attacked by the player. City and National factions will cause members of these factions to attack the player. Other factions will not cause an attack, but may refuse service.
Condemned
Players who are condemned may or may not be able to interact with NPCs such as shopkeepers, and guards who dislike a player will likely not help players in need. If a shopkeeper will interact with the player, the prices will be drastically higher than normal prices.
Denounced
Guards will not help or attack players, and most NPCs are interactable. However, the merchant will increase the price to the player and decrease the price of items he or she purchases from players.
Neutral
Neutral players can interact with most NPCs and can receive help from guards. Shopkeepers prices will be somewhat high, but these are the normal prices. Guards will also assist the player.
Friendly
Guards will assist the player, and may have quests for the player. Merchants may give a discount on items that are for sale.
Honored
Guards will be friendly and are more likely to offer quests to the player from time to time. Merchants give a discount and a chance to purchase rare items from them. Earnings from sales to the NPCs will also be increased. Some NPCs may offer quests not available to lower tiers of reputation.
Revered
Guards will protect you, even against others who are friendly or neutral to them, and are likely to offer quests. Merchants will offer a significant discount when purchasing from them, and will pay more for goods sold to them. Guards, Merchants and other NPCs will offer quests to the player when available.
Illustrious
Guards will protect the player, even against other players who are honored with the faction. Merchants will be quite generous, and offer epic-level items when available. They will offer almost retail rate when selling to them. Any quests available will be offered, with a chance for epic items and increased rewards.