During the Crystal War, these military tacticians often served as high-ranking officers in allied forces across Vana'diel. Extensive knowledge of ancient martial theory granted Scholars (SCH) the ability to wield dual schools of magic, between which they would alternate depending on the situation at hand. Available after completing the quest, A Little Knowledge.
The abilities available within Stratagems correspond to the school of Arts that the scholar currently has activated. If the Scholar does not have an Arts effect active, no abilities are displayed.
Stratagems do not have a recast time. Instead, they operate on a charge-based system. A Scholar consumes a charge when he/she activates a Strategem. After a certain amount of time, the charge is refreshed. The maximum available charges and the amount of time until a charge is restored are based on the Scholar's level. (see table)
When using the "/recast" text command with a specific Strategem (such as "/recast Celerity"), the log displays the amount of time remaining until a new charge is generated, as well as the current number of charges available.
When displayed, it appears like this: [Celerity] 1:13 (2)
Active stratagems remain available for up to one minute or until a compatible spell is cast. Spells cast that are incompatible with an activated Stratagem have their normal effect.
Addendum: White and Addendum: Black are exceptions to this rule. Once active, they modify your current arts effect and remain active as long as that Arts effect is active.
As of March 2012, all stratagems use a single charge.