Clue scroll

A Clue scroll is a random reward from killing monsters or playing minigames. Players are able to have one of each tier of clue scroll at a time. Taking another clue scroll from the floor is not possible if you already have one of the same tier. You cannot receive a clue scroll through Lootshare. Clue scrolls are the start of a Treasure Trail - a rewarding treasure hunt around RuneScape.

Easy clue scroll (level 1)
Easy clue scrolls are usually easy, short and without risk. These clues can be obtained as a drop from lower level monsters, pickpocketing H.A.M. members, or as a reward from the Evil tree, Shades of Mort'ton (minigame), Caskets, or Miscellania.

Medium clue scroll (level 2)
Medium clue scrolls are slightly more complex, featuring coordinate clues (requiring a Sextant, Watch and Chart to complete). Killing Pyrefiends is the fastest way to obtain a level 2 clue. Another method of obtaining Medium clue scrolls for players who have access to fairy rings and the Protect from Melee prayer is to kill Abyssal leeches in the Abyssal area. They have 2600 Life Points and have spawns away from other aggressive creatures in the Abyssal area which allows them to be easily AFKed, only requiring the player to top up their Prayer points when they get low or switching to a different spawn spot when they become unaggressive.

Hard clue scroll (level 3)
Hard clue scrolls are usually longer and harder. Coordinate clues will always summon a Zamorak wizard (inside the wilderness) or a Guthix Wizard (outside the wilderness) excluding one in the duel arena. Both wizards use magic. Level 3 clue scrolls are usually rewarding, since they include rune items, and the more expensive Treasure Trail rewards (such as Third age armour).

Elite clue scroll (level 4)
Elite clue scrolls were released on 4 August 2010. This clue scroll can be obtained as a drop from various Boss monsters (GWD bosses, Dagannoth Kings, Kalphite queen, the Skeletal Horror, Bork and the Corporeal beast), metal dragons and Strykewyrms. This level has the hardest and most exhausting clues, having the possibility to encounter a Guthix wizard that can poison whilst treasure hunting. The Elite clues have three types of puzzles that cannot be encountered on a lower level. The Celtic knot, which may also be encountered, asks for patience to solve. The Compass challenge includes a compass pointing in the direction of the next clue, but without the distance. A Scan involves an orb that you need to scan the area with in order to find the next clue. The rewards usually average between 100-200k but may be much more rewarding.

Trivia

 * If you have two (or more) reward caskets at the same time and open them both quickly, the first one will give you the reward while all the others will just give you a new clue scroll.
 * It is possible to have more than one clue scroll of a given level if the player has one on the ground and then receives one from a magical chest.
 * It is possible, though very uncommon, for the player to receive the same clue multiple times in a row, regardless of occurrence.
 * The Items Kept On Death shows that clues have a value of 1 coin.
 * The highest monster that drops a level 2 clue scroll is a Giant sea snake, with a level of 150. While Jellies are only level 78, they drop level 3 clues. Ankous drop level 3 clues as well, you can find them in level 4 of the Stronghold of Security.
 * If you die while doing a clue scroll, you will keep it automatically, unless you're in the Wilderness.
 * When killed in the wilderness holding a clue scroll, the killer will receive nothing and you can run back and get the scroll.
 * Hellhounds seem to be the best way to get hard clue scrolls; they are easy to kill and drop them quite commonly.
 * Prior to the 18 May 2015 update, players were able to have only one clue scroll at a time.