QCT

QCT is an abbreviation for quarters casting time, a bonus that used to be achievable 4% of the time when wielding a weapon set with two HCT modifications for the same attribute. The May 21st 2010 update capped reductions on casting time to 25% (with the exception of single effects exceeding this cap), preventing further reductions through the use of weapon upgrades.

Mechanics
Casting time modifications stack, with each HCT for a specific attribute giving an independent chance of halving casting time. If two such modifications trigger together, the time will be reduced to 25% of the default. There are two types of HCT modifications: attribute specific ones offer a 20% chance to halve casting time for just that attribute and generic ones, that offer a 10% chance of splitting casting time for any spell.

There are several ways to create the potential for quartering casting time:
 * 4% chance from two HCT modifications of the same attribute.
 * 2% chance from one HCT attribute specific mod and one generic mod.
 * 1% chance from two generic HCT mods.

Acquisition

 * 4% chance sets


 * A wand inscribed with "Aptitude not Attitude" plus a focus of the same attribute with a core of Aptitude.
 * One pair of weapons with this combination is the 40/40 set, which also has an increased chance to halve spell recharge times.
 * A staff with an Adept head and inscribed with "Aptitude not Attitude".


 * 2% chance sets
 * A wand inscribed with "Don't Think Twice" plus a focus with a core of Aptitude.
 * A wand inscribed with "Aptitude not Attitude" plus a focus with a core of Swiftness.
 * A staff with a Swift head and inscribed with "Aptitude not Attitude".
 * A staff with an Adept head and inscribed with "Don't Think Twice".


 * 1% chance sets
 * A wand inscribed with "Don't Think Twice" plus a focus with a core of Swiftness.
 * A staff with a Swift head and inscribed with "Don't Think Twice".