The party will be held in Lumbridge Crater. There will also be a prologue to a multi part year-long 20th Anniversary Quest series later in January. The Grand Party itself will offer several buffs and rewards, in addition to a 10% XP bonus. You can also claim your 20th Anniversary outfit and cape.
Additionally, the party will feature weekly events, with each event focusing on a different feature of the game and world. Patch notes were also published including several fixes and improvements such as:
- As the festive period has now finished, Gielinor has returned to its pre-Christmas state.