GrimGrimoire[b] is a 2007 real-time strategy video game developed by Vanillaware and published by Nippon Ichi Software (Japan, North America) and Koei (Europe) for the PlayStation 2.

The story follows Lillet Blan, a trainee witch who is sent into a repeating cycle of five days after her school is attacked by an evil wizard seeking the hidden Philosopher's Stone.

The player commands units called familiars, each having strengths and weaknesses against the other, with the goal of either destroying the opponent's bases or surviving waves of enemies.

GrimGrimoire was born from Vanillaware staff wanting to create their version of StarCraft, beginning development after completion of their first title Odin Sphere.

Upon release, the game met a generally positive reception; praise went to its narrative and implementation of RTS gameplay on a console, but many faulted the audio and controls.

The character Lujie Piche crossed over into Nippon Ichi Software's Soul Nomad & the World Eaters as part of the two companies' collaboration.

GrimGrimoire is a two-dimensional (2D) side-scrolling real-time strategy (RTS) video game; players take the role of trainee witch Lillet Blan, who completes both story missions and optional challenge levels.

[5] During the RTS segments, the player takes the role of Lillet Blan, who directs the action while the multi-floored battle area is shown from a side-scrolling perspective.

[8] Establishing runes and summoning Familiars require Mana, magical energy gathered from crystals on some floors using units from the Glamour class.

[7] The action of GrimGrimoire takes place entirely within the Tower of Silver Star, a magic school with ancient roots, over a repeating cycle of five days.

In the game's backstory, the Archmage Calvaros cooperated with fellow wizards Gammel Dore and Lujie Piche to create the Philosopher's Stone, a powerful magical object.

On her fifth evening, Lillet wakes to find the Tower under attack from Calvaros's released spirit, who has killed the other teachers and is seeking the Philosopher's Stone.

Visiting the Tower years later in her role as Mage Consul, Lillet meets remaining residents again, and learns that Lujie vanished into another world.

[1][11] While development on Odin Sphere was ongoing, Nippon Ichi Software heard that the Princess Crown team had formed their own studio.

[12] This was part of a transition within Nippon Ichi Software of being willing to work with external studios while acting as publisher, as their earlier policy had focused exclusively on in-house development.

[11] The agreement between the two was that Vanillaware to handle development and all associated costs, while Nippon Ichi Software focused on sales and promotion while owning the game IP.

[14] According to differing estimates by Kamitani, the project took between six months and a year to complete, a schedule attributed to deadlines set by Nippon Ichi Software.

[1][12][15] The production of GrimGrimoire combined with the delayed release of Odin Sphere left Vanillaware drained of funds, forcing Kamitani to take out a flexible loan of 20 million yen to keep the company afloat.

[1][12] Kamitani later said his state of excitement over the project led to many of the decisions abound the story, deriving thematic cues from the universes of Atelier Marie: The Alchemist of Salburg and the Harry Potter series.

[15] A notable part of the collaboration between Vanillaware and Nippon Ichi Software was the character Lujie Piche, who also appeared in Soul Nomad & the World Eaters.

Lujie was originally designed for GrimGrimoire, but Nippon Ichi Software thought the character would be a good fit with the visuals and style of Soul Nomad.

[37][38] The remaster included graphical enhancements for the new consoles, an art gallery, fast forward and mid-battle save options, adjustments to the Hard difficulty setting, gameplay expansions through the incorporation of skill trees for Familiars and powerful magical attacks, and a new voice cast.

[15] The Nintendo Switch version of GrimGrimoire OnceMore was the twenty-fourth bestselling retail game during its first week of release in Japan, with 3,524 physical copies being sold.

[8] Adam Biesenner, writing for Game Informer, struggled to recommend it due to issues with its controls and gameplay despite enjoying the deeper experience; this opinion was backed up by fellow writer Joe Juba.

[44][48] The graphics earned high praise despite a lack of variety in battle arenas,[7][8][48][50] while the music and voice acting met with a mixed reaction.

[7][8][49] There was praise on its implementation of RTS elements on consoles despite the limited scope; common complaints arose from rough controls and a lack of meaningful progress.