Every quest that was in OSRS at the time of its release is also canon in RS3 with few exceptions.
In RS3, Romeo & Juliet was reworked into Gunnar's Ground, so the canonicity of Romeo & Juliet is questionable in RS3. Similarly: Doric's Quest was replaced with What's Mine is Your's; Prince Ali Rescue was replaced with Stolen Hearts and Diamond in the Rough (this also caused minor changes to Icthlarin's Little Helper); and Black Knight's Fortress was replaced with Death of Chivalry (this caused minor changes to Recruitment Drive).
Several quests were also heavily reworked which calls into question whether their original events and any past events referred to during them canonically happened in RS3. These include: Druidic Ritual; Death Plateau; Demon Slayer; Rune Mysteries; and Cook's Assistant.
Also worth noting that, so far at least, the OSRS and RS3 teams appear to deliberately avoid outright contradicting each other regarding any events that occurred prior to year 169 of the 5th age (the year the events in RuneScape took place during until after The World Wakes was released) which leaves a distinct possibility that any events referred to in either game that occurred during or before 168 of the 5th age are canon in both games (this weirdly includes the RS3 World Guardian appearing and speaking to Guthix immediately prior to Guthix's attempt to banish Seren from Gielinor at the end of the 3rd age, which does work by some time travel rule sets but is still strange to think about).
18-Sep-2021 19:59:53
