All three combat types also rely on the player's defence and hitpoints stats. The defence stat determines how likely one is to block an incoming attack, whereas hitpoints determine how much damage that can be taken before dying. The prayer stat, while seeming subtle at first, can turn the tide in a fight.
Prayers such as the protection spells can render a person invulnerable to enemy attack, and they provide numerous protections. The most powerful and recent prayers can also set back the enemy in different ways. When fighting other types, players generally switch armor to best suit their opponents attack. Warriors fighting mages will usually wear dragon hide armor, a type armor with high "magic defence". To counter this, the mage may use a dagger, a weapon which armor high in "magic defence" is usually vulnerable to.
In addition, the equipment a player is holding, the potions he has drunk, how much food he has, luck, and countless other factors all combine to determine who will win the battle.
Illegal trading
Jagex has explicitly banned two types of trading: selling and buying RuneScape accounts, and trading RuneScape items and services for things outside of RuneScape, such as real world money or benefits in other online games. Despite the fact that Jagex will instantly ban anyone violating these rules, there is an active market for these illegal trades. On any given day one can find hundreds of RuneScape accounts being sold on eBay (however many of the bids are false). A very profitable website, buyrunescape.com, sells Runescape items for very low prices. Yet, Jagex has not taken any action against these pirate sites.
There are also entire websites springing up now, offering "professionally gained" items in exchange for cash. Items like the dragon chain body are on sale for $500 or more - The market is huge, but Jagex has insisted it won't allow it. (Particular reference to Sony, who decided to cash in on the trading of EverQuest items by opening up a legal trading ground)