Tele Block

Tele-block requires a Magic level of 85 and can only be cast on another player in the Wilderness. If successful, it will prevent that player from using teleportation for 5 minutes. However, if the targeted player is using the prayer Protect from Magic the duration of the tele-block is ~1 minute and 40 seconds. It is very useful in player killing. Unlike most spells though, tele-block does not take effect the instant the caster casts it. The victim is still able to teleport until the spell has finished its animation. However, this is too fast for most users to react in time.

If you are tele-blocked, teleportation spells on your spell list will be black, as though you do not have the required level. When you get tele-blocked, there is no magic that physically hits you, so it is difficult to realise, unless you attempt to teleport.