From Ryzom Wiki
| Slow Movement|
Slow Movement is an affliction; a negative status effect that handicaps the target.
It is also known as Snare.
A creature under the effect of Slow Movement will simply move slower than usual while under the effect. The degree to which they are slowed varies based on what kind of Slow Movement is used.
Slow Movement as spell
Players are able to inflict Slow Movement on a target using the Slow Movement spell from the Offensive Affliction Magic skill. This spell is first available at level 12 magic. Like with all affliction spells, a link must be maintained to keep the target slowed. This slows movement speed by about 20%.
Players can increase their chances of resisting a Slow Movement Affliction spell by wearing jewelry that raises their Forest resistance.
Slow Movement by critical
The Slow Movement caused by a critical hit to the legs is not a magical effect and thus Forest resistance will not help resist it. Creatures that are immune to Slow Movement spells similarly are not immune to this effect.
Enemies using Slow Movement
Since homin mages are capable of casting Slow Movement affliction spells, it may be used against you in PvP, though it's not very popular there.
Najabs can inflict yet another type of Slow Movement on their enemies with their spit attack. This also is not a magical effect and thus able to bypass both Forest resistance and Slow Movement immunity.
Creatures immune to Slow Movement
Slow Movement immunity only applies to the Offensive Affliction spell; not to Slow Movement caused by critical hits or the Najab special ability.