Main article: Magic - The Basics#Casting_Spells
Clicking on the book on your side interface brings up the magic spellbook. This will show all of the spells available to you within the game. If the picture of a spell is darkened, it means that either you do not have a high-enough level to cast it, or you do not have the runes in your inventory to do so. If a spell is lit up, then it means your level is high-enough to cast it and you have enough runes in your inventory.
To cast any spell, just left-click on its icon and then click on your desired target. Some spells can only be cast on monsters and players, while others can only be cast on yourself or items.
The spellbook interface as shown in-game.
To get more information on a spell, simply move your mouse cursor over its icon.
You can use the three buttons in the bottom-right corner of your magic spellbook to change the order that spells are listed. By default, this will be in level order, but you can click the 'fireball' icon to put all of the combat spells first or the 'teleport' icon to put all of the teleport spells first. You can use these ordering buttons with any of the spellbooks.
To the left of the ordering buttons, at the bottom of the spellbook interface, there are 2-4 buttons that remove spells from your spellbook view. Each button removes a different type of spell: you can click the 'crossed swords' icon to hide/unhide all combat spells, the 'teleport swirl' icon to hide/unhide all teleport spells, the 'random blobs' icon to hide/unhide all miscellaneous spells, and the 'graph' icon to hide/unhide all skill spells. Clicking on these icons again will add them back to your spellbook view.
On the bottom-left of the magic spellbook interface is an icon that looks like a shield. This shield represents 'defensive casting'. If you click this button, you will gain Defence experience whenever you cast combat spells, at the cost of receiving a reduced amount of Magic experience. To return to casting your spells normally, simply click the button again.
A description of the spell and a list of which runes are required will be shown when you move your mouse over it. Each required rune has two numbers shown below a picture of it. The first number indicates how many of that rune you have and the second number indicates how many are required in order to cast the spell.
The numbers will be in red when you do not have enough of those runes.
