In order to attack and kill creatures or defend you against others a player must first be in attack mode by pressing the "a" key. Once in attack mode, the cursor is red (normally it is green). The "a" key can toggle attack mode on and off. To target an adversary simply left click on it while in attack mode.

The target will be selected, and a health bar will appear below it showing how much health it has left. Remember to toggle off attack mode before going in town and clicking on a friendly citizen. If a friendly townsperson is attacked, this can cause the local guards to attack and kill the unlucky player. Also, attacking and killing townspeople will lead to the player having an evil alignment (his name will be red).

However, there is a target protection system that can be toggled on and off with F4. If it is off you will be able to attack townspeople and kill them, and when it is on you will be warned that player protection is on. The term "townsperson" used here encompasses the horses, children, shopkeepers, and other assorted peaceful populations in the towns.