After you use a skill, there is a certain amount of time where you can't use the same skill, or other skills. This is what is called Cast Delay.
There are technically three forms of Cast Delay: Animation Delay, After Cast Delay and Skill Delay.
|ASPD||After Attack Delay|
|ACD||After Cast Delay/Global Delay|
|VCT||Variable Cast Time|
|FCT||Fixed Cast Time|
|FAD||Fixed Animation Delay|
Animation delay is the amount of time it takes your character to go through the motion of its cast (e.g. Heal), attack (e.g Meteor Assault), or throw animation (e.g. Acid Demonstration), which can be reduced by higher ASPD or a technique called "Animation Delay Cancel" (*). Another skill cannot be initiated, until you have finished the animation for a previous one.
After Cast Dealy
After Cast Delay is a skill specific, fixed amount of time after using a skill, during which no other skill can be initiated. Gear that reduces "after-cast" or "re-use" delay will shorten this time. Even at 100% reduction, this delay is hard-capped at about 300ms or 3 skills per second. NOTE: Most rAthena servers do not set this delay by default and thus can spam skills much faster, especially high rates.
Skill Delay prevents you from using a particular skill again, but you can use other skills. It's a grey colored over an individual skill, instead of grey over all of them, and is not reduced by anything. For instance, consider the Endure skill. You can't use it again, even if the effect runs out, for several seconds, but this would be disastrous if you couldn't use other skills in the interim. Only reuse of Endure is prevented for the full duration.
How After Cast Delay Works
The ability to spam one skill, is limited by the highest of those three factors.
Jupitel Thunder for example has neither Skill Delay nor After Cast Delay, and therefore is only limited by the Animation Delay of the cast animation the High Wizard has to go through. That means that increasing ASPD will increase over all DPS (granted, the Cast Time is low enough/instant), because it allows you to reuse the skill much more frequently.
That means generally, if you are able to reduce the After Cast Delay of any skill that has no Skill Delay, to a value smaller than it's Animation Delay, ASPD or "Animation Delay Cancel" will help to reuse the skill more frequently.
The effect of ASPD or "Animation Delay Cancel" greatly varies between skills. As a general rule of thumb, enemy-targeted offensive skills usually have ASPD-dependent animation delays, while ground-targeted and support skills usually have fixed animation delays, but there is no particular hard-and-fast rule for this. That means though, that if your skill's Animation Delay is not really affected by ASPD, "Animation Delay Cancel" becomes more viable.
Some skills do lose their Animation Delay entirely when Instant Cast (150 dex, or 100% Cast Time reduction) is achieved. Examples are Acid Demonstration and Increase Agility. One would conclude that this means their re-usability greatly increases, but thats weirdly enough, not the case.
Most skills which can be affected by reductions have a cast time split in two sections:
Variable Cast Time
- It covers 80% of the total cast time of a skill.
- It can be reduced by stat values like: DEX, INT.
- It can be reduced by skills like: SuItalic textffragium, A Poem of Bragi.
- It can be reduced by equipment and cards which state so: Isilla's Card, Kathryne Keyron's Card.
Fixed Cast Time
- It covers 20% of the total cast time of a skill.
- It cannot be reduced by stat values.
- It can be reduced by certain skills like: Sacrament, Radius.
- It can be reduced by equipment and cards which state so: Shadow of Nydhog.
To reduce all variable cast time the sum of your DEX and INT values have to be of 530. Make note however that DEX has double the value of INT.
[(DEX*2)+INT] = 530
What combination of stats you use to reach that value is up to you. Do consider that it's the total value of a stat. Which means that job bonus, equip bonus and card bonuses count as part of your total.
Full Cast Time Formula
- baseCast: Base cast time of a skill.
- ΣCastRed%: Sum of reductions that affect variable cast time.
- Like: Suffragium, effects like Isilla's Card or Kathryne Keyron's card.
- MaxFixedRed: Highest reduction modifier that affects fixed cast time.
- For example: If both Sacrament (50%) and Radius (20%) are active only Sacrament will work.