The Grimoire of Alice is a spellbook owned by Alice Margatroid. In the PC-98 canon, she uses it against the heroine in the Extra Stage of Mystic Square, where she refers to its powers as "the ultimate magic"; "The Grimoire of Alice" is also the title of the BGM for this fight.
In the Windows canon, Alice is known to carry around a locked book; while never officially stated, this is widely assumed to be the grimoire, kept sealed due to her habit of never fighting at full strength. In Imperishable Night, she was seen carrying a book that appears to be the grimoire. Sunny Milk refers to Alice as possessing "a grimoire that shines wonderfully with all seven colours of light", though the truth of this statement is unclear.
Marisa Kirisame insists that The Grimoire of Marisa "is absolutely not a copy of Alice's grimoire in any way".