A strange device is an item used in the Hot & Cold challenge of a beginner or master clue.
The master clue strange device can be obtained by talking to Jorral in the outpost northwest of West Ardougne, while the beginner clue strange device can be obtained by talking to Reldo in the Varrock Palace library. The player must have an active clue step directing them to one of Jorral or Reldo to obtain a strange device, but once obtained it does not need to be returned and can be kept in the bank. Note that one must have completed Making History before Jorral will give them a strange device for a master clue.
The strange device changes temperature as the player moves about. Its temperature is based on the distance of the treasure from the player, measured in the number of steps it would take to reach the treasure, ignoring any obstacles. The warmer the key gets, the closer the player is to the treasure. Clicking "Feel Strange device" gives information on its temperature, and if solving a master clue, will deal 3-8 damage to the player each time as well (which can be fatal).
A list of possible locations can be found here.
|The Device is Ice Cold
||You are no where near the dig spot.
|The Device is Very Cold
||You are very far away from the dig spot.
|The Device is Cold
||You are far away from the dig spot.
|The Device is Warm
||You are getting close.
|The Device is Hot
||You are close.
|The Device is Very Hot
||You are very close.
|The Device is Incredibly Hot
||You are almost at the dig spot.
|The Device is Visibly Shaking
||You are on top of the dig spot - dig now!
While following a master clue, when you dig at the dig spot you will have to face enemies depending on whether the area is single or multi-combat, so remember to bring combat equipment, food, and potions. If the area is single combat, your opponent will be a Brassican Mage that uses a typeless projectile attack. In a multi-combat area, you will instead face three Ancient Wizards which use different combat styles. The melee wizard can also poison you, so a means of curing poison should also be brought if your destination is in a multi-combat area.