[Your name here]'s casting is interrupted.

[progenitor]

Why do I get this message?

How do I prevent this from happening?

What stat do I need to raise and how do I go about raising that stat?

-p

[Secrenja]

You get it beccause your casting was interrupted. You can get interrupted if...
1.You move while casting a spell(sometimes your spell will work, but alot of times it stops casting)
2.A monster attacks you while you are casting it(with exceptions like the one stated above)

Some of the AF armors cut down on casting interruptions. The spell "aquaveil" also helps cut the chances down(useful in the beginning). The other way is to time your castings, like start a cast right after a monster hits you so chances are you will finish your cast before its next attack.

[kiks]

although sometimes, my spell still gets interrupted even if i'm not moving, before the monster is even hostile towards me! Weird...

[Secrenja]

Maybe you were running right before you started casting it? Like if you select to start casting just as you stop, Thats happened to me before.

[Icemage]

Physical attacks, as well as some special attacks from enemies, can interrupt spellcasting if they hit you while you are still in the process of casting a spell. I don't know that any stat really affects it - the best way to avoid spell interruption is to time your spells so that you start casting them right before or right after you get hit by an enemy. The above-mentioned Aquaveil DOES cut down on the spell interruption chance, but I consider it an enormous waste of time and MP.

Note that it is always a good idea to not panic in battle, especially when you are getting hit as a mage. If you take damage, stay calm, wait for the next attack, then immediately launch your next spell as the monster's attack goes off. If you just start casting "whenever" you'll waste time, and maybe get yourself killed in the process.

As for the your spells being interrupted right at the beginning of a fight, if a party member attacks your target (turning it red) before your spell completes, your spell will immediately interrupt. Avoid casting on enemies until they turn red, unless you are the designated puller for your group.

Icemage

[Morphy]

Most likely it is due to network latency.

The server is only going to let you cast if it sees you as stationary. Your cliet, however, always fakes it to make it look like you are doing exactly what you control it to do. So even though you may have stopped before casting, the server may not know that yet due to it receiving the packets informing it that you want to cast a spell _before_ the packets that tell it to stop moving it get there. This happens more than you would think

[david_blaine]

^^^yea, I dont know if thats true but I get my spells interupted for no reason alot too. I dont see any other explanation but damnit it bugs as hell.

[Andry]

even david blaine's getting his magic tricks interrupted...

[Seance]

Spell casting interrupted occuring even when I knew for certain that I stopped dead in my tracks before casting the spell confused me as well.

I don't know if this is the reason why it occurs but I think it may be because of tiny lag. When spell casting interruption occured I noticed I was always running, then stopping, then trying to immediately cast the spell after stopping. If you try waiting 1 to 1.5 seconds after you stop then cast the spell, it dramatically reduces the rate of the interruption happening.