Activated abilities always start with a cost, followed by an arrow (), and then the effect. Mission cards tend to not have activated abilities, because they already cost build points to play. Many Battle cards have activated abilities that work only for one attack or battle. Units, especially in the Character arena, often have one or more activated abilities.
Some card abilities are good all by themselves. Shields 1 (Each unit gets -1 power as long as it's attacking this unit.) is the best example of this. Others are limited only by how often you can use them: Pay 1 Force Evade 1 (Prevent up to 1 damage to this unit.) is a great ability as long as you have the Force to use it.
Other card abilities work better in combination. Strength of Hate gives a unit +3 power, which gives it the chance to do up to 3 more damage for one attack. When you play it on a unit that has Critical Hit, such as Jango Fett, it's even more powerful-not only does Jango have a chance to do up to 3 more damage, he has three more chances to roll a natural 6 and deal extra damage.
Here are some strategy tips that will help you get the most out of your card abilities:
Use the Force wisely. Many activated abilities require you to pay Force. Unless you save up for several turns, you'll usually only be able to use one or two of these abilities each turn.
To tap or not to tap? Abilities that require the unit to tap present two problems. First, that unit cannot attack during the battle phase. Second, and more importantly, that unit cannot retreat during the retreat step either.
The keyword is . . . Virtually every unit has one or more keywords following its card type. Obi-Wan is a Jedi; Jango Fett is a bounty hunter, and so on. Many card abilities affect cards based on these keywords.