- Not to be confused with Litmus Strip.
Due to the prevalence of Mary Sues in fiction and the desire of good writers to curtail them, various litmus tests have been written wherein authors can test their original characters for Sueness. None of them are 100% reliable, so taking several is recommended.
- The Original Mary Sue Litmus Test by Dr. Merlin - designed with Gargoyles fanfic in mind, but applies widely.
- The Universal Mary Sue Litmus Test - contains different sections for original fiction, fanfic, and RPG characters. Also has some "de-Suifiers" to give back points.
- The Writer's Mary Sue Test - seems intended for characters in original fiction.
- Mary Sue Test - seems designed for original fiction. Based on Dr. Merlin's original litmus test, the Writer's Mary Sue Test, TV Tropes' list of Sue traits, and the now-lost Original Fiction Mary Sue Litmus Test. Contains de-Suifiers.
- Harry Potter and the Mary Sue Litmus Test by Priscilla Spencer - for Harry Potter OCs. Based on Dr. Merlin's original litmus test.
- Mary Sue Litmus Test: LOTR Adaptation by Winterfox - for Lord of the Rings OCs. This is the test linked to by the original PPC Basic Charge List and several others.
- LotR Mary-Sue Litmus Test - also for Lord of the Rings OCs, oddly enough.
- Siren's PotC Mary-Sue Litmus Test - for Pirates of the Caribbean OCs. Based on the Universal Mary Sue Litmus Test and Araeph's PotC Litmus Test (now lost).