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Psionic powers spring from sentient minds. Even an undead creature or a being that has no physical form can create a reserve of inner strength necessary to manifest powers, as long as it has an Intelligence score of at least 1. Vermin possessed of a hive mind ability are an exception to this rule.
A psionic power is a one-time psionic effect. Psionic characters and creatures need not prepare their powers for use ahead of time. They either have sufficient power points to manifest a power or they do not.
A power is manifested when a psionic character pays its power point cost. Some psionic creatures automatically manifest powers, called psi-like abilities, without paying a power point cost. Other creatures pay power points to manifest their powers, just as characters do.
Each power has a specific effect. A power known to a psionic character can be used whenever he or she has power points to pay for it.
First you must choose which power to manifest. You can select any power you know, provided you are capable of manifesting powers of that level or higher. To manifest a power, you must pay power points, which count against your daily total. You can manifest the same power multiple times if you have points left to pay for it.