Every character starts play with Action Points. Action points provide players with the means to alter d20 rolls in dramatic situations. After a die roll, but before the GM reveals the results, you can decide to spend an Action Point. For a character, spending an Action Point adds 1d6 to the d20 roll, helping you get closer to or exceeding the target number. An Action Point can be applied to a single die roll when making an attack roll, a skill check, an ability check, a level check, or a saving throw.
In some cases (as noted in the rules), a character must spend an Action Point to perform a certain activity. An Action Point spent in this way does not provide an increase to a d20 roll.