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Action Speed
Action Speed increases the rate at which any animation that does NOT have a loading bar is played.
Including but not limited to:
- Swinging weapons
- Recovering from swings
- Switching items
- Reloading
- Drinking potions
This also includes the casting animation that occurs after finishing fully casting a spell. See Spell Casting Speed for more information on this.
Interaction Speed
Regular Interaction Speed and Magical Interaction Speed increases the rate at which all loading bars are played, except for Spell Casting loading bars.
Regular Interaction Speed affects loading bars on usually physical objects, while Magical Interaction Speed affects loading bars on usually magical objects. See the hyperlinked pages for more specific examples.
Spell Casting Speed
Spell Casting Speed increases the rate at which the loading bar when casting a spell is played.
A common misconception is that the Magic Staff has a longer cast time than other casting implements like the Spellbook, when all implements actually share the same casting time which rely only on the spell and the Spell Casting Speed stat. The reason Magic Staff feels like it casts slower is because the animation of casting which occurs after the cast loading bar is finished is considerably longer, which does vary for each casting implement. This animation is after the loading bar is finished, and therefore scales off of Action Speed, NOT Casting speed.
Formula
Action Speed, Regular Interaction Speed, Magical Interaction Speed, and Spell Casting Speed are all rates that impact their respective durations the same way.
Modified Time = Base Time / (1 + Rate * Scaling)
Where Rate refers to the Action/Interaction/Casting speed. See Examples.
Assume Scaling = 1 for all items except Surgical Kit's which is mentioned below.
Since Scaling = 1 for every case but one, the formula can be simplified to:
Modified Time = Base Time / (1 + Rate)
Currently, there is only the Surgical Kit that has non-100% Scaling which is 50% Scaling on the interaction time to use the surgical kit (Regular Interaction Speed).
For this, a modified formula must be used
Modified Time = Base Time / (1 + Rate * Scaling)
Note that the only difference is that Rate is multiplied by Scaling. For all other items, Scaling can be assumed to be 100%(1), making this equivalent to the first provided formula.
Examples
For example, with 50%(0.5) Casting Speed, a 1s cast time spell will take
1s / (1 + 0.5) = .66s
or 2/3rds of the base cast time, or a 33% shorter cast time.
With 100%(1.0) Action Speed, a 2s swing time will take
2s / (1 + 1.0) = 1s
or 1/2 of the base swing time, or a 50% shorter swing time
Note that this results in diminishing returns in the amount of time saved by getting a higher Rate.
This makes it impossible to make any Modified Time 0 seconds long. Even with a Rate of 500%, the Modified Time is
1 / (1 + 5) = 0.16s
or 1/6th of the base time, or 83% shorter time.