As well as fighting the computer controlled monsters and characters you can also choose to directly fight with other players. Fighting against other players is often a lot more dangerous because they can also use spells and prayers. Also watch out because their friends could be lurking behind a tree ready to finish you off!

Killing other players can potentially give great rewards if they are holding valuable items. However attacking another player sets your alignment to 'evil', and a skull appears above your head to indicate this. As longer as your player is marked with a skull the risk is greater. If you die you will drop everything you are holding (you won't get to keep your 3 best items like you normally do!). If you play for 20 minutes without attacking anyone, the skull will disappear and the 3 item protection will work again.