Skill capture

Skill capture is a method of learning new skills in Guild Wars. The way it works is that players slay an enemy boss (and only a boss) and then invoke the Signet of Capture to see a list of the skills this boss had. The players can then choose which skill to capture in the signet. Once a skill is chosen, it will be learned by the character and will be stored in that character's Skill Inventory. A skill capture can be cancelled without using up the signet.

For more information on using the Signet of Capture itself, see the article Signet of Capture.

Capturing Elite Skills
Using a Signet of Capture is the only way to learn elite skills in PvE play. Elite skills are available from bosses in the advanced areas of the game, including the Crystal Desert, Southern Shiverpeaks and the Ring of Fire Islands. For a comprehensive list of elite skills avaliable and the bosses and locations where these skills can be acquired, see the elite skills list.

Note: A player can only equip one elite skill at a time. However, if you already have an elite skill equipped and you capture another one, you will be able to use both while you are still in that explorable area. If you had several Signets equipped, you can even use more than 2 Elite Skills. As soon as you leave the area (walk to another, map travel or some other way) you will find that all elite skills except for the left-most one on the Skill Bar are gone and replaced with empty boxes. The captured skills have been learned and unlocked, though, and are available in the Skill Inventory.

Per the 04/26/2006 update, Signet of Capture gives 250xp per character level when an elite skill is captured.

Capturing Non-Elite Skills
The primary purpose of the Signet of Capture is for capturing elite skills, however, you get your hands on your first Signet of Capture in Kryta, long before you reach any boss that has an elite skill. So what to do with your fancy new toy? There are quite a few non-elite skills that are worth capturing:

Capturing Quest-Reward-Skills
When possible, gaining skills as quest rewards is the preferred method, because the skill doesn't require gold or Skill Points. Skill points shouldn't be wasted.

Note: There are about 140 skills available for your primary and secondary profession together. About half of these are available as quest rewards in the Prophesies campaign. That leaves about 75 skills that you must buy if you want them. Buy directly from a skill trainer or indirectly using a Signet of Capture. Either way costs one Skill Point and gold. By the time you finish the last mission, you'll have about 50 to 60 skill points. You will quickly run out of skill points if you ignore skills that come from quest rewards and instead try to buy those skills.

However, if a skill is very valuable to you and available from a boss much earlier in the game than from a quest, consider spending a skill point to capture it early.

In Factions rather than giving skills as quest rewards, skill points are given, making it easier to purchase or capture wanted skills.

Capturing Skill-Trainer-Skills
Capturing a skill that is otherwise only available from Skill Trainers is always worth considering, for one reason:  The fact that some skills are available from bosses much earlier in the game than from a skill trainer! And being able to use a valuable skill a few missions earlier can make a huge difference. To find skills that are available from bosses earlier than from the respective skill trainer, refer to the list of skills by capture location.

However, it is also important to notice that you can still gain skill points after you've reached level 20 by gaining experience. So if you have a skill you need to buy ASAP, do not worry about it, get it! You're most likely to end up with more skillpoints as you progress through the game.