A wide variety of A, B, C and S grade weapons in the game can have a special
ability, or SA for short, applied to them. Except dual swords (their SA cannot
be chosen) all other weapons can have only one of three possible SA's.
You cannot exchange or upgrade a weapon with SA on it at Blacksmith of Mammon
- you have to remove SA first (can be done at Black Marketeer of Mammon, located
in the most major towns).
All SA's stack with other buffs - if you have a weapon with SA Empower, the empower buff will increase your even more.
For adding a SA to your weapon - you need a soul crystal of matching stage and color (depending upon the desired SA). For weapons up to B Grade, you can ask the blacksmiths in Giran and Aden for the list of possible SA's (the weapon must be disarmed and in your inventory) and the required crystal color for each of them. For A and S Grade, the Blacksmith of Mammon is necessary. Also some amount of gemstones and money are required for the process.
Any enchantments on a weapon are not lost when applying SA, and also the weapon with SA can be further enchanted without losing it's SA (unless over-enchantment fails). Using blessed enchant weapon scroll (rare item available from drop at high level Raid Bosses and Grand Olympiad) is much safer way to over-enchant your weapon - then you don't lose weapon and it's SA, only enchant status turns to +0.
For dual swords the SA is gained automatically by over-enchanting the weapon to +4 or more, no crystal needed. However, keep in mind that enchanting a weapon from +3 to +4 or more has a chance of evaporating and turning it into crystals of it's grade type. The chance of breaking it is about 30% (unconfirmed).
Detractors of the critical period hypothesis point out that in these examples and others like them (see Feral children ), the child is hardly growing up in a nurturing environment, and that the lack of language acquisition in later life may be due to the results of a generally abusive environment rather than being specifically due to a lack of exposure to studies are problematic; isolation can result in general retardation and emotional disturbances, which may confound conclusions drawn about language abilities. Studies of deaf children learning American Sign Language (ASL) have fewer methodological weaknesses. Newport and Supalla (1987) studied ASL acquisition in deaf children differing in age of exposure; few were exposed to ASL from birth, most of them first learned it at school.