Weapons students and schools can and cannot possess.
This is just based on my opinion, so… YMMV.
Also NSFW because some of these weapons can be a bit controversial in regards to IRL (also just in case)
Weapons Students/School can possess:
• Pretty much any small arm: from pistols all the way up to rocket launchers, even flamethrowers (in Megu’s case), you name it. However, bows and crossbows have not made an appearance (yet).
• Tanks and other armored vehicles: students have been shown to operate them like actual cars (Iroha is the textbook example of this).
• Helicopters: almost about anyone can get one, from students to adults.
• Howitzers and Artillery: Trinity and Gehenna have been shown to possess these cannons at their disposal. Nagisa’s EX skill even has her commanding them to be fired.
• Quadcopter drones: by far, the only drones to appear in the game. Shiroko has one, Ayane has one, and Students from Odyssey have been shown to have one in the 7th PV.
• Mortars: Hibiki and, as now, Suiko have been shown to have them as their primary weapons. Saki got one in her L2D. And Gehenna’s Prefect Team also have them.
• Any Sci-Fi weapon: Ask Millennium.
• UCAVs: Miyako in her Swimsuit has been shown to operate one in her EX Skill.
• Chemical weapons (edit): Saya exists. Though nerve agents, similar to the ones used in WW1 are probably illegal to use in combat.
• Probably warships (edit): Helmet gangsters have one in the Abydos summer event. So it’s possible for schools to possess them.
• Magic (edit): Their halos and mystics probably give students such abilities. >!Aris used magic in Volume EX to empower Kei.!<
• Melee weapons and bayonets (edit): Saori and Wakamo have them respectively. And it’s possible, with the right materials, can cause permanent damage to a student (Misaki is a textbook example of this).
Weapons that Students/Schools cannot or have not been shown to possess:
• Cruise missiles: Volume 3 has implied that these weapons possibly cannot be owned by schools. Arius only used one to disrupt the Eden Treaty and it was made by the Nameless Priests.
• Bows/Crossbows: no student has been shown to wield one. And it is unknown if any does or will.
• Dark magic (edit): given that Nature’s Beauty is not an official club. It’s stands to reason that the dark magic they use for their tomes is illegal under both Kivotos and Hyakkiyako law. It’s possible magic from Terrors is also illegal or unethical.
• Jets and Bombers: the only type of aircraft(s) that students or schools have NOT been seen with.
• Kamikaze/One-Way Attack drones: Loitering munitions in general have not been seen in the game. Though given their controversial use in the Russo-Ukrainian and Iran wars. It’s unlikely Nexon would want to put a Shahed-136 in the game.
• Ballistic missiles and ICBMs: Given their destructive capabilities. It’s unlikely for any school to possess them.
• Nuclear Weapons in general: GSC and Sensei: “NO.”
• Thermobaric weapons (edit): upon reinvestigation, apparently, Thermobaric weapons and other WMDs are banned under GSC law, no student or adult can have one. And it's implied they can kill students and citizens of Kivotos.
• Anti-halo weapons (edit): Although very rare to find or make one, these weapons can kill a student, which is (not surprisingly) a very very VERY huge offense and crime in Kivotos. >!As seen with Seia and Atsuko in the bad timeline illustrations!<
I may have missed some. If so, could you comment it.
Let me know in the comments on what you think.