Since the beginning of Toontown Rewritten's development, many important elements of the game's storyline are unveiled in forms of an alternate reality game (ARG). The main purpose of ARGs is typically to move the game's story forward by employing transmedia storytelling. Many ARGs take place on online platforms such as Toontown Rewritten's official website or an external website created by the Toontown Rewritten Team, and sometimes also take place directly in-game.
- Main page: The 26th
Toontown Rewritten's storyline began with a story arc revolving around a date known as the 26th. The first 26th ARG on Toontown Rewritten's website was published on November 26, 2013 (2002), by LL-TERMINAL43. The 26th is an anomaly caused by Doctor Surlee, who is previously known as Gyro Gearloose, when he activated the time reversal and traveled back in time to October 26th of 1998, at an attempt to rewrite Toontown's timeline. Due to the imperfections of Doctor Surlee's pocketwatch that he used to activate the time reversal, this by effect caused unforeseen anomalies to occur years afterward.
The 26th story arc concluded on March 13, 2019 (2008), when the Silly Meter stabilized Toontown's timeline and ended the anomalies of the 26th.
Current ARGs often foreshadow future events and updates that tie into Toontown Rewritten's storyline. An example of this is the Cog memo ARG in which players had to decrypt three Cog memos, with one Cog memo mentioning plans of a "C.F.O. Project" from the Cogs to distribute their products across the entirety of Toontown and have highly confidential assets be shipped via Cashbot freight trains to Cashbot Headquarters. After the Cog memos were decrypted, the Toon Resistance commenced Operation: Crash Cashbot Headquarters in order to stop the "C.F.O. Project".
- Alternate reality game on Wikipedia