The cooldown time of skills is the time it takes after activating the skill until it is ready to be used again. Using a skill or being interrupted while casting will cause the skill to begin its cooldown time. While a skill is recharging, the icon for the skill is covered in red and has a white number counting down how many seconds are left until the skill is ready. When the skill is available to be used again, the red covering and white number will disappear and the icon will appear normally. Some skills or effects, such as Torch Bearer's Deep Freeze, can lengthen the cooldown time of skills; other skills or effects such as a Flag of Celerity can shorten cooldown time.
If a skill is aborted by the player or because of a lack of target, the recharge will not begin and the skill will be available again for immediate use.