Special attacks

Some weapons in RuneScape have special attacks available for them. There are many types of special attacks, from temporary boosts in stats, to strikes dealing extra damage. They are activated by the player by clicking on the special attack bar under the Combat Options interface. Special attacks have an energy bar that is drained when you use the attack; this is drained of varying amounts according to which weapon is used. Some exceptions to this are the following: the Barrows set effects require neither special attack energy nor do they deplete any special energy upon activation; moreover, a charged Dragonfire Shield dislodges dragonfire upon operating it, which also does not expend special energy since it doesn't rely on any.

The special energy bar regenerates at a rate of 10% every 30 seconds, and requires 5 minutes to regenerate from empty to full. The bar will not regenerate while a player is logged out, nor would it regenerate if a player had their bank window open.

The energy bar is related to the player, not to the weapon - in other words, changing weapons does not change the special energy bar. Interestingly, special attacks' names are not shown anywhere in-game; instead, they are revealed on the RuneScape website.

Dragonfire Shield
The Dragonfire Shield can discharge a fireball hitting around 25 damage at an opponent. It doesn't use any special attack energy, but the attack can only be used once the shield has cooled down every two minutes.

Barrows set effects
When a player wears ALL of the items of a Barrows set (e.g. Verac's helm, brassard, plateskirt and flail), it has a set effect. The effect has a 25% chance of occurring and neither consumes special attack energy nor depends on any special energy whatsoever.

Trivia

 * The Dragon axe's special attack, Clobber, formerly lowered the target's Magic and Defence stats by 10% when it hit, but it was changed on 24 March 2014 to a skill-boosting special that mirrors the Dragon pickaxe's special.
 * Of all the Barrows set effects, Dharok's Wretched Strength is the only one that doesn't consist of a purple aura animation.