What ways are there to cast spells faster?

Question

Some spells take significantly longer than an action to cast, but can be cast much quicker than that under some conditions:

• Wish (1 action). Duplicates a spell of 8th level or lower.
• A Chronurgy Wizard's Arcane Abeyance (1 action, doesn't have to be the caster's). A spell of 4th level or lower can be stored for up to an hour, though you have to spend the time casting it beforehand.
• An Order of Scribes Wizard's Awakened Spellbook (normal casting time). This allows you to cast a spell as a ritual without having it take the extra 10 minutes. (Alternatively, you can see this as saving you no time, but you get a free spell slot that can be used on a subset of spells.)

I keep on thinking that there are a number of items that do this, but I seem to mostly be misremembering. Are there any more ways to quickly cast spells? (I'm excluding prep time that can be done outside of battle when totaling how quickly spells can be cast.)

Answer 1

Try Glyph of Warding

Pre-casting the spell into a Glyph of Warding would be the most straightforward way to cut down the casting time later on. Release it with a trigger action.

The main limitations on this are what spells you can store (must target a creature or area, or conjure something) and that you cannot easily move the glyph. So for combat purposes you either need some way to bait the opponets to where it is, or you need shenanigans like a Demiplane with glyphs on its interior walls. But it does cut down the casting time to essentially nothing.

Other methods

Apart from this, the methods that you have seem to be the main ones. In addition, there are a few fringe cases, most of which deal with messing with time in general (so they are not specific to cast spells faster, they serve to do anything faster)

• Time Stop. Will not replace the casting time with a shorter one, but will buy you 6-24 seconds after accounting for the turn it costs you to cast it.

• Plane Shift to the Feywild, and hope that upon leaving it, you roll lucky on the time warp table and turn days into minutes or hours, or use a wish to remove negative outcomes. This gives you a 30% chance to speed up the time you need to cast the spell (if you have Wish, you might as well just use it directly instead). In older editions of D&D there were slow-time demiplanes in Eberron that would have made this work reliably.

• Contingency will allow you to trigger spells based on circumstances, which can include a predefined trigger like snapping your fingers. The selection is limited casting times of one action, so the speed-up is minimal if anything.

• Spell Gem are a magic item from Out of the Abyss that allows the caster to store a single spell and cast it as one action if on their spell list (kudos to smbailey for finding this).

• Quicken Spell (as suggested in Phoenices) The Sorcerer's metamagic turns a full Action into a Bonus Action. Not technically changing the casting time.

• Boon of Quick Casting likewise allows you to cast one spell of up to level 3 as a bonus action instead of an action.