A slice of birthday cake is an item available during some of Old School RuneScape's birthday events by taking a slice off the birthday cake. Eating the cake heals 2 hitpoints.
- During Old School RuneScape's first birthday, it was blue in colour, and was available by taking a slice off the birthday cake in Prifddinas.
- During Old School RuneScape's second birthday, it was available by taking a slice off the birthday cake in Varrock Square, although the colour of the cake has been changed to yellow.
- During Old School RuneScape's fifth birthday, it was available by taking a slice off the birthday cake in the Falador Party Room, although the colour of the cake has been changed to purple, adding alongside decorations of runes.