Rum is only available for purchase from Honest Jimmy at Trouble Brewing, at a cost of 20 pieces of eight. It serves as a single-use teleport back to Trouble Brewing. Upon drinking the rum, the player will become intoxicated and collapse, after which point they will awaken outside the lobby of the minigame. The rum can not be consumed beyond level 20 Wilderness.
While under the intoxicating effects, the player will exclaim: My Liver! My Liver is melting!
Attempting to drink the rum while already at Trouble Brewing will result in the message: It hardly seems worth drinking the 'rum' here.
It is often more time-efficient to use the minigame teleport to get to Trouble Brewing, as it costs nothing, and can be used every 20 minutes.