Type of Feat: Metamagic
Prerequisite: Ability to cast 4th-level spells.
Specifics: Quickened spells can be cast instantaneously, making them invulnerable to interruption. A quickened spell is not vulnerable to arcane spell failure when wearing armor and does not provoke an attack of opportunity. Quickened spells also prevent counterspelling. A quickened spell is cast as a free action, and another action can be attempted within the same round, including the casting of another spell. Only one quickened spell can be cast per round.
Use: Quickened spells occupy spell slots four levels higher than normal.
For a list of all spells which can be enhanced by this feat, see: Category:Spells that can be Quickened.
Automatic Quicken Spell
Automatic Quicken Spell is an epic metamagic feat. It requires the feat Quicken Spell, Spellcraft 30 and the ability to cast ninth level spells (either arcane or divine). Automatic Quicken spell allows spells of 0-1st levels to be cast as quickened, without using higher level spell slots. It can be taken multiple times in order to quicken spells up to ninth level.
Despite the description, quickened spells are still vulnerable to arcane spell failure.
The statement about counterspelling for quickened spells being prevented in the official description is specious, because counterspelling as a game feature was never carried over from NWN to NWN2.
Also, it appears NWN2's handling of this feat allows for quickened spells to be vulnerable to disruption if damaged while casting, likely due to the fact that it's not truly a free action but takes 3 seconds (see below) to cast a quickened spell in the game.
A normal spell takes a full round to cast (6 seconds of game time) and actually "fires" the spells' effects at about the half-way point in the round (3 seconds). A series of 4 such spells would therefore take 24 seconds to fully cast and 21 seconds for all of the effects to be dealt to their targets. A quickened spell is supposed to fire immediately according to PnP rules. However, the NWN2 engine does not fire a quickened spell immediately. Instead, it cuts the spell casting time in half (to 3 seconds with the effects happening at 1.5 seconds).
By handling quickened spells in this manner, NWN2 does not properly handle the stacking of quickened spells with normal, non-quickened spells.
Example 1 (Normal spell sequence of 4 spells = 24 seconds) Mage Armor (6 secs.) Shield (6 secs.) Mirror Image (6 secs.) True Strike (6 secs.)
Example 2 (Quickenend spell sequence of 4 quickened spells = 12 seconds) Quickened Mage Armor (3 secs.) Quickened Shield (3 secs.) Quickened Mirror Image (3 secs). Quickened True Strike (3 secs).
Example 3 (mixture of normal and quickened spells = 18 seconds) Quickened Mage Armor (3 secs.) Shield (6 secs.) Quickened Mirror Image (3 secs.) True Strike (6 secs.)
Since quickened spells are free actions in PnP, the 3rd example reveals the problem - NWN2 uses up 3 rounds instead of 2 for this type of sequence. Both examples 2 and 3 should end up as taking only 2 rounds, however, in NWN2 the 3rd example takes 3 rounds to complete.
-However, example 2 is also not possible in PnP as you are restricted to one quickened spell per round. Basically how this turns out is that you can achieve the same effect as PnP if you use twice as many quickened spells, since you have to chain cast them, which makes it less efficient. If you follow example 3, which is the correct sequence for PnP, then it is slower than PnP rules.
While this is an incorrect implementation of the Feat, some may still consider it useful to fire off spells faster than normal. However the cost of quickening spells (using spellslots 4 lvls higher) combined with a severely crippled implementation (not free action, disruptable) in the NWN2 engine makes this feat considerably less viable than in PnP.