Recharge time

Recharge time is the minimum period that a character must wait after using a skill before they can attempt to activate it again. Skills that are interrupted or disrupted by knock down also have to wait to be recharged. Failing skills are ready immediately; they do not need to recharge. The visual indicator of a recharging skill is a darkened skill icon that gradually lightens as if a clock-hand was sweeping through from noon to midnight.

Mechanics

• A skill begins recharging at the exact moment the skill is completed or prevented.
• Before a skill is used, its recharge time can be affected by other skills, environmental effects or weapons (HSR). For example, Quickening Zephyr lessens recharge times while Energizing Wind lengthens them.
• Disabling a skill can prolong its recharge time but cannot shorten. For example, Blackout disables any skill of its user for 5 seconds. If one particular skill was recharging and its remaining time was 3 seconds, then it will be prolonged to 5 seconds. If another skill had 30 seconds left until recharge, it will not be affected by Blackout and will continue recharge normally.
• While a skill is being activated, the user can alter its recharge time by invoking a stance. For example, if you activate Serpent's Quickness before completing a casting of Meteor, the recharge time will be shortened.
• Boosts from multiple skills cannot combine to reduce the time by more than 50%, although a single skill's effect can bypass this limit.
• A skill that requires adrenaline cannot gain adrenaline while it is recharging.

Skills that reduce recharge time

Reduces other skills' recharge times

• Serpent's Quickness ends if under 50% maximum health
• Quickening Zephyr also makes skills cost more energy
• Trapper's Speed only for traps
• Practiced Stance (elite) only for Preparations
• Mantra of Inscriptions reduces Signets' recharge times
• Mantra of Recovery only for Spells
• Symbolic Posture reduces your next Signet's recharge time
• Celestial Haste (PvE only)
• Glyph of Swiftness only affects spells
• Iron Mist only Air Magic spells that target a foe
• Deadly Haste only for half-ranged spells, also decreases activation
• Deadly Paradox only for assassin skills, also decreases activation, disables attack skills for 10s
• Ghostly Haste affects only spells cast in earshot of a spirit
• Ritual Lord (elite) only for Binding Rituals
• Weapon of Quickening (elite) only for Spells and Binding Rituals
• Avatar of Lyssa (elite) only applies to dervish enchantments
• Lyssa's Haste only applies to dervish enchantments
• Ebon Battle Standard of Wisdom Spells cast within the ward have a 44...57...60% chance of recharging 50% faster (PvE only)
• Volfen Agility Volfen skills recharge 66% faster (PvE only)

Conditionally reduces its own recharge time

• "None Shall Pass!" for each foe knocked down
• Foul Feast if it removes disease
• Discharge Enchantment if target was hexed
• Flame Djinn's Haste if a foe is hit
• Mirror of Ice (elite) if a foe hexed with Water Magic is hit
• Siphon Speed if target was moving
• Pious Assault if a dervish enchantment is removed
• Signet of Pious Light if a dervish enchantment is removed
• Signet of Pious Restraint if a dervish enchantment is removed

Skills that involve instant recharge

• "On Your Knees!" instantly recharges all of your stances if adjacent to knocked down foe.
• Flourish (elite) instantly recharges all of your attack skills and gives energy for each skill recharged.
• Renewing Smash instantly recharges itself if it hits a knocked down foe.
• Needling Shot instantly recharges itself if target is under 50% health.
• Oath Shot (elite) instantly recharges all skills but itself if target is successfully hit.
• Determined Shot instantly recharges all attack skills if target is not hit.
• Bitter Chill instantly recharges itself if foe has more health than you.
• Signet of Sorrow instantly recharges itself if target has a dead pet or is nearby to a corpse.
• Verata's Sacrifice instantly recharges itself if you have 3 or fewer minions.
• Inspired Enchantment/Revealed Enchantment instantly recharges itself if a monster skill enchantment is removed.
• Inspired Hex/Revealed Hex instantly recharges itself if a monster skill hex spell is removed.
• Keystone Signet (elite) instantly recharges all signets except itself.
• Persistence of Memory instantly recharges interrupted spells.
• Glyph of Renewal (elite) instantly recharges your next spell.
• Assassin's Promise (elite) instantly recharges all skills if enemy dies while affected by this hex.
• Moebius Strike (elite) instantly recharges all other attack skills if it hits a foe below 50% health.
• Anguished Was Lingwah instantly recharges Ritualist hexes when dropped.
• Reclaim Essence (elite) affects binding rituals.
• Ritual Lord (elite) instantly recharges if a binding ritual is used while under its effect.
• Soul Twisting (elite) affects binding rituals
• Farmer's Scythe instantly recharges itself if it hits more than one foe.
• Pious Renewal (elite) instantly recharges itself when it ends
• Air of Superiority 10% chance of recharging all skills every time you earn experience from killing an enemy (PvE only).

Skills that recharge by a morale boost

• Storm of Swords (PvE only)
• Celestial Stance (PvE only)
• Star Shine (PvE only)
• Star Servant (PvE only)
• Celestial Haste (PvE only)
• Celestial Storm (PvE only)
• Star Strike (PvE only)
• Celestial Summoning (PvE only)
• Resurrection Signet
• Sunspear Rebirth Signet (PvE only)

Skills that increase recharge time

• Rage of the Ntouka adrenaline skills have a 5 second recharge
• Energizing Wind increases all skill recharge times by 25%
• Withdraw Hexes increases its recharge by 20...8...5 seconds for each hex removed
• Word of Censure increases its recharge by 20 seconds if used on a foe with less than 33% health
• Auspicious Incantation disables your next spell for an additional 10...6...5 seconds
• Diversion increases the recharge time of the next skill used by a foe
• Glyph of Sacrifice also causes instant casting with an additional 30 second recharge
• Repeating Strike increases its recharge by 15 seconds if it misses

Notes

The Guild Wars 2 Wiki also has an article on Recharge time.

• Some skills, such as the Dervish forms, are disabled upon ending and their recharge cannot be decreased.
• Some skills do not have a recharge time.
• Although not a skill, the Power Up Box in Rollerbeetle Racing also provides an instant recharge.
• Skills that recharge skills do not replenish any adrenaline (some people say "charge" regarding adrenaline).
• The Essence of Celerity consumable reduces recharge times by 20%.
• Although not stated explicitly in their descriptions, both a Powerstone of Courage and a Seal of the Dragon Empire recharge all skills when used due to their Morale Boosts.