From Ryzom Wiki
Slow Attack is an affliction; a negative status effect that handicaps the target.
It is also known as Slow, which is sometimes confusing with the Slow Movement affliction.
A creature under the effect of Slow Attack will perform all their action slower than usual while under the effect. This applies to melee attacks and ranged attacks as well as all spell castings. The degree to which they are slowed varies based on what kind of Slow Attack is used.
Players can increase their chances of resisting a Slow Attack Affliction spell by wearing jewelry that raises their Forest resistance.
Another way to inflict Slow Attack is to score a critical hit on the target's arms with either a melee or a ranged weapon. This Slow Attack is not a magical effect and thus Forest resistance will not help resist it. Creatures that are immune to Slow Attack spells similarly are not immune to this effect.
Players can inflict yet another type of Slow Attack if they use a blunt damage type melee weapon with the special "Slow" stanza. This also is not a magical effect and thus similarly able to bypass both Forest resistance and Slow Attack immunity.