Added Effect is a Support Materia in Final Fantasy VII. When linked with a variety of Magic and Summon Materia, it either provides a 20% chance to inflict the status effect associated with the Materia if equipped on a weapon, or immunity to it when equipped on armor.
Added Effect is found in the Cave of the Gi. This is the only way to obtain the Materia, meaning to have multiple, the player must master one. This requires 100,000 AP, meaning that it is best to equip weapons and armor with Double or Triple AP when attempting this. Cave of the Gi is an unrevisitable location, so the player should pick the Materia up when they have the chance.
|Contain||Petrify, Confusion, Stop|
|Hades||Sleep, Poison, Confusion, Silence, Frog, Small|
Added Effect has two uses: on weapons, it provides a 1/5 chance to inflict a status effect after attacking, and on armor, it makes the wearer immune to a status effect. The status menu will list statuses that a character defends against or can inflict with the paired Materia. The paired Materia does not need to have learned the associated spell that has the status yet for it to work with the Added Effect; e.g. the Time Materia provides both Slow and Stop effects even if the player hasn't leveled the Materia up to learn the Stop spell.
Both applications of Added Effect are beneficial. In dungeons where enemies commonly inflict a negative status, and the player does not have an accessory that provides immunity to it, Added Effect can be used to defend against it. In other cases, Added Effect should be paired on a weapon to provide the chance to inflict a status. The only danger to this is that many enemies have immunity to some statuses, so it is important to check first, or simply pair it with a Materia that can inflict multiple statuses as one may have a chance of working.
One drawback to using Added Effect for physical attackers is, though the Added Effect Materia itself has no stat changes, the paired Materia will. It is best paired with Magic Materia that provide the smallest detriment to Strength possible. Using the Materia on Cloud or Yuffie can good as they have both a high Strength and Magic, making them useful at either ability. Nonetheless, using Added Effect on physical attackers is potent, as though the chance is lower than using the Materia to cast a spell, it will not consume MP, and a turn is never wasted as the damage is still done.
Later in the game, the player can obtain Ribbons on all party members making pairing Added Effect on armor redundant. Though larger enemies later on tend to resist status effects, not too many resist Slow, making Time Materia a consistently good pairing with it. Pairing Added Effect with Hades has the best effect in both weapon and armor.