Triggered Abilities are abilities that apply when a specific event or condition occurs.
Written using the following syntax:
[Trigger condition,] [effect.]Triggered abilities begin with the word When, At, or Whenever followed by the time or condition under which the ability will trigger, followed by the effect that happens.
Examples: Aggressive, Death Cloud, Leader of Men
A triggered ability only triggers once each time its trigger event occurs. However, if one event contains multiple occurrences of a trigger event the ability will trigger multiple times. For example, an ability that triggers Whenever a figure is downed from this unit, will trigger three times if another ability is used on that unit that says Down three target figures on an enemy unit. (As long as three figures are actually downed.)
Triggered abilities need only be ready when the trigger event occurs; they need not be ready when the trigger actually resolves. For example, a figure ability that triggers When this unit is dealt damage will trigger and resolve even if damage dealt to that unit also downs the figure causing this ability to be ready.
Some triggered abilities are optional. Usually this is marked by the word may before the effect of the ability. If a played chooses not to use an optional triggered ability, no part of that ability happens. (Note that some abilities may be entirely optional, while others may just have optional pieces.)
A triggered ability may have a cost in order to use the effect, but it is still considered a triggered ability. For example: Whenever this unit is given a ranged combat order, it may spend one order point to gain 2 blue dice until end of turn. This is still considered a triggered ability, though the effect is only gained if the cost is paid.