As of this market's time of creation, two quests have been added to Oldschool Runescape in 2024: Children of the Sun, and Defender of Varrock.
As of this market's time of creation, the OSRS development roadmap, which goes to summer 2024, includes "multiple new quests" as part of the Varlamore release on March 20th, While Guthix Sleeps in the summer, and "more new quests" in the Varlamore Part 2 release later in the summer. It doesn't comment one way or the other, but we can guess, that there may be additional quests released in the later parts of the year past the end of that roadmap.
So it looks like we're due for an unusually quest-release-heavy year! But there remains an open question of exactly how unusually quest-release-heavy it's going to end up being. Let's try to figure it out!
Market resolution will be based on the number of entries dated to 2024 in the OSRS Wiki's list of quest release dates as of the start of 2025. (With a bit of flexibility to e.g. wait a couple days past the new year or check a prior page version from a couple days earlier, in case of wiki-vandalism.)
1,000
3.00Final quest-list for the year, per wiki currently:
Children of the Sun
Defender of Varrock
Twilight's Promise
Perilous Moons
At First Light
The Ribbiting Tale of a Lily Pad Labour Dispute
While Guthix Sleeps
The Heart of Darkness
Death on the Isle
Meat and Greet
Ethically Acquired Antiquities
The Curse of Arrav
That's twelve in total. This accords with numbers on the wiki over the past couple weeks, so seems unlikely to be a temporary inaccuracy.