A measure of the actual time it takes to fully activate one power and become ready to activate another, after adjusting for the small additional delays introduced by the game's animation system. The term is derived from "Arcanaville", the forum name of the poster who first discovered and described this phenomenon.
In Arcanaville's own words, from Re: some meanings that im un aware of
- "ArcanaTime" is a term coined to represent the calculated time that a power takes to execute, based on its published cast time. It's always longer due to the fact that the game servers process events in a particular way, and that way makes it impossible to "bookend" two attacks together any closer than about 0.132 seconds, and when an attack completes the game doesn't flag the character as ready to use another attack until the end of the current 0.132 second clock tick it's processing.
- The formula1 for it is ArcanaTime = [RoundUp(CastTime / 0.132) + 1] * 0.132, and the thread which describes where this formula comes from is here. It's used to calculate DPA of attacks and also the total DPS of chains of attacks because its been demonstrated to very closely estimate the in-game performance of an attack chain where the attacks are queued and fired as quickly as the game will allow.
1 The original post uses "Round()" instead of "RoundUp()". This is an error.