Using FX Items

To use a magic item or psionic item, it must be activated. The three ways to activate FX items are described below.
Command Word: If no activation method is suggested either in the item description or by the nature of the item, assume that a command word is needed to activate it. Command word activation means that a character speaks the word and the item activates. No other special knowledge is needed.
The Knowledge (arcane lore) skill might be useful in identifying secret command words or deciphering clues regarding them. A successful check (DC 30) is needed to come up with the word itself. If that check is failed, succeeding at a second check (DC 25) might provide some insight or clue to discovering the command word or phrase.
Activating a command word FX item is an attack action and does not provoke attacks of opportunity.
FX Completion: This is the activation method for scrolls. To use an FX completion item safely, a character must be high enough level in the right class to cast the spell already.
Activating an FX completion item is an attack action and provokes attacks of opportunity.
Use Activated: This type of item is activated simply by use. Use activation is generally straightforward and self-explanatory.
Many use-activated items are objects that a character wears. Continually functioning items are practically always items that one wears. A few must simply be in the character's possession. However, some items made for wearing must still be activated. Although this activation sometimes requires a command word (see above), usually it means mentally willing the activation to happen. The description of an item states whether a command word is needed.
Unless stated otherwise, activating a use-activated FX item is either an attack action or a free action and does not provoke attacks of opportunity, unless the use involves committing an action that provokes an attack of opportunity in itself. If the use of the item takes time before an effect occurs, then use activation is an attack action. If the item's activation is subsumed in use and takes no extra time, use activation is a free action.
Use activation doesn't mean that if a character uses an item, he or she automatically knows what it can do. A character must know (or at least guess) what the item can do and then use the item to activate it, unless the benefit of the item comes automatically.