After reading this expansion front to back I can now give my full review on this product.
This is definitely a SMT:Persona add-on! Several mechanics fit within for a world befitting a JRPG. The game mechanics do make it difficult to plan a game around Persona 3, or earlier titles and works best for Persona 4 or 5 type settings. The theming of this add on is really good, and definitely gets the creative juices flowing. The city of Hawthorne is a great start to making you're own modifications.(I've based mine as a Martha's Vineyard type city) The adventure is very bare bones, which allows the players to do what it is they please.
The adventure comes with a plentitude to get you started on your own world. How to get into the shadow world, characters, and main story beats. It doesn't include fine knit NPC's as it's main goal is to give you that power. The game does want you to include a few NPC's that marge into the character's backstory, and give them an arcana.
Character creation is a lot of fun. Choosing a playbook, an arcana, and several moves is great as it allows you to have greater expression in characters. The Arcana are numerous, and some double up on what I would consider powers or roles. The mechanics are nicely explained, until they're not(more on that later). The ability to include base game playbooks, and how to change these playbooks to use in the base game is incredible! And very welcome for players who look at the base game playbooks and have a favorite.
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I am however, not a fan of the Highschool being split in four houses, or that the school has dorm rooms. It might make more sense in a Japanese sense, but the school and city are all in America. The school system seems to be an attempt to meld American and Japanese school systems, which I think is done rather confusingly. Students are required to help with jobs around the school, live in the school in the dormitories, and are forced to participate in school festivals. As High schoolers are 'required' to stay in the schools dormitories what is the point of the entire city, if the students are trapped in the school?
There are just several very small issues that I have with this add on. The playbooks often mention something, that isn't mentioned at all anywhere else in the entirety of the book. The Shadow has a move that mentions having a 'Non-Human' form, but nowhere else in the book does it mention having one, what the requirements are, or even what it is. I can only assume that it means that the Shadow playbook is like Morgana or Teddy from the Persona franchise, having an animalistic form in the shadow world and having a human guise in the real world. The Laundry list feature for The Prisoner is a great nod to Persona 5, but lacks in explaining itself. As it has several contradicting verbiage uses. Missing a roll says not to clear a mark on the investigation track. What is the investigation track? When would I clear a mark? On a hit it says to mark off an investigation. Is that a clear? Do I lose a mark? If that's the case, how do I gain one?
There are several issues where the DM and the players have to infer as to what their base mechanic means, and what it does. And this could differ from different perspectives of the entire table. I think the weirdest thing I've noticed is the use of the word 'malus' in the Arcana Palace move 'No Place Like Home' where it says to apply any 'malus' like normal. Malus being, a banking term for profit loss. And it's the only time it's ever mentioned or used in the book.
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Overall, I give this add-on a glowing review. The few things I nitpicked in detail were only the few times I had a rough experience with trying to translate or explain to a player. There are rough edges that require a bit of sanding, but as it stands this is a great addition for those who love MASKS and the Persona series as a whole.