The Rapier in Runescape is a very thin sword, most effective for piercing. Its speed is equal to a shortsword. It was used by Gentleman Mallard until his disappearance at sea. The sword was later found by Smith of Mos Le'Harmless, who will sell it to players for 25,600 coins, so you need to complete Cabin Fever first. The stab and slash attack bonuses of the rapier are opposite compared to the Rune scimitar.

To be able to understand Smith and purchase the rapier, the player must either have a Book o' piracy in their inventory or have completed the Rocking Out quest. Talk to Smith and select the cutlasses option in the dialogue box.

Players require level 40 Attack to wield the rapier. It is the stabbing brother of the rune scimitar and can be used as an alternative by members. The rapier is one of the most effective one-handed weapons for stabbing.