Transmutation (錬成合成, Rensei Gōsei?, lit. Alchemical Synthesis) is a gameplay feature from Star Ocean: Anamnesis through which weapons can be turned into another weapon of higher rarity. To do it, players must go to the Transmute option on the Items menu. This process requires a base weapon that must be level 10 or higher, along with five weapons of the same rarity as the base weapon, as well as FOL.
Synthesizing these materials together will produce either: a weapon of higher rarity by 1 (which is selected at random) or, in the case of 5☆ weapons, a weapon coin. The latter is determined by the type of the transmuted base weapon; for example, transmuting a 5☆ one-handed sword will produce a single 5★ OHS Coin. These coins can be used to exchange for a 5☆ weapon of the player's choice at the Item Exchange option in the shop menu. It is recommended that players use it to obtain elemental-imbued weapons.