The Missing Score is Barret's ultimate weapon in Final Fantasy VII. It is obtained from the Sister Ray in Midgar during the Raid on Midgar, only if Barret is in the party. The Missing Score has very high stats and eight linked Materia slots, and a unique mechanic: it deals damage based on the total AP of the Materia in its slots, though Materia in these slots cannot gain AP. The weapon is potentially extremely powerful, due to the possibility of inducing the overflow glitch when using it. The player can equip it to Barret or throw it or sell it for 1 gil, but there is only one copy in the whole game.
The Missing Score is obtained in a treasure chest at the Sister Ray in Sector 8 during the Raid on Midgar. The chest is only available while Barret is in the party, and the weapon is permanently missed if not picked up. This makes Barret significantly less useful than other party members due to a lack of access to his ultimate weapon.
Missing Score has the highest Attack stat of any of Barret's weapons, and one of the highest Magic stat boosts of any weapon in the game. It deals damage based on the total AP of all Materia in its Materia slots in the following formula:
This is then modified by the attack's power; for normal attacks, the multiplier is 1.0. Unlike most other damage modifiers, each character's ultimate weapon applies the damage modifier after all other modifiers, instead of modifying the attack strength of the weapon itself.
To achieve a base 1.0 damage multiplier, the weapon needs to have approximately 150,000 AP on it. To reach the 4x damage multiplier that is comparable to characters with their ultimate weapons, the weapon needs to have approximately 630,000 AP on it.
Missing Score is Barret's ultimate weapon, and the damage dealt with it depends on the AP of all the Materia equipped on it. The weapon has eight linked Materia slots and provides a large +49 bonus to Barret's Magic stat. This makes Barret ideal for spellcasting, as he can equip a large amount of Magic and Summon Materia at no detriment to his physical damage with normal attacks or Limit. As a result, by using the weapon, the player should give Barret a spellcasting role. Mastered Independent Materia can also be very effective to strengthen Barret further.
Missing Score is ideally used with mastered Materia. The player can master Materia in the Northern Cave, most easily using Cloud with Apocalypse and Cid with Scimitar for triple AP, or equipping weapons and armor that provide double AP (including Barret's W Machine Gun and Drill Arm). One minor drawback is that Barret is best not equipping Materia that does not accumulate AP.
Though Missing Score requires a lot of investment to reach its full potential (needing approximately 630,000 AP equipped), its potential exceeds most ultimate weapons. It allows Barret to more reliably hit 9999 damage with normal attacks than other characters can with their ultimate weapons, and also allows Barret to hit 18 different 9999 attacks with Angermax, a level 3 Limit, if enough AP is equipped. This can allow Barret to deal more damage with a Limit than any other character, on a Limit that charges faster than a level 4 Limit. Reaching this level requires large amounts of investment, however, and is not necessary in most cases.
The damage overflow glitch can be induced using this weapon in extreme cases, much like Vincent's Death Penalty. This can be done by equipping eight mastered Knights of Round Materia on the weapon. Though extremely difficult to achieve, this allows Barret to defeat almost any enemy, including the Emerald Weapon, in a single hit, though doing so will also require maxing Barret's Strength stat with Power Sources. It is still not possible against Ruby Weapon due to its high Defense.
The only time one would use Barret's Max Ray over Missing Score is if they do not have enough Materia with sufficient AP to make Missing Score useful. However, as long as the player as around 150,000 AP to make Missing Score's damage equivalent to a 1.0 multiplier (which would be comparable to equipping any normal weapon), Missing Score is still the best weapon for Barret to equip.