In order for a critter to use a power against a target, they have to be in the same state, either astral or physical. Astral forms cannot affect physical targets, and physical forms cannot affect astral targets (see The Astral World, p. 312, CRB). An astral critter that can materialize can affect physical targets if they do so, however, and dual-natured critters can interact with the astral plane as easily as the physical one.
Each entry lists several common characteristics of each power:
Type: Like spells, powers may be either mana (M) or physical (P). Mana powers do not affect nonliving targets, whereas physical powers cannot be used in astral space or to affect astral forms.
Action: Most powers require a certain type of action (Simple or Complex) to activate. Some are always on and require no action to activate; these are listed with an Action of “Auto.”
Range: All powers have a range; this is listed as Line of Sight (LOS), Touch, or Self (the power affects only the critter itself). The Line of Sight rules for spellcasting (p. 281, CRB) also apply to critter powers. Unless otherwise noted, a power may only be used on one target at a time.
Duration: This entry indicates how long the power’s effect lasts.Powers that are constantly in effect (those with an Action of Auto) have a duration of Always.
Instant powers take effect and vanish in the same action, though they may have lasting effects (damage, for example).
Sustained powers may be maintained over time at no effort or cost. Because these powers are innate, the critter is not subject to any strain or modifiers for keeping the effect going the way sustained spells do—although normal sustaining rules apply if the critter casts and maintains a spell through Sorcery. Even taking damage will not distract the critter from its ability to sustain. As with sustained spells, line of sight does not have to be maintained after the power takes hold of its target. Critters may sustain a number of powers (or multiple uses of the same power) at one time equal to their Magic.
Permanent powers must be maintained for a specific period of time before the effects become permanent, as noted in the power’s description.
Some powers have a Special duration. The duration of the power’s effect depends on other factors; these are noted in the description.