Do HCT mods stack with Fast Casting?

Hey all,

Was puzzling over modding some more fancy gear for my Mesmer when I realized I don't know for sure if and how the reduced cast time from points invested in Fast Casting stack with the equipment mods that give a chance at HCT (half casting time.)

Do they stack at all? If not, does that mean a Mesmer with points in Fast Casting would never get HCT benefit?

If they do stack, how does the HCT calculate? Is the base cast time reduced by just 50% when the mod triggers, or is the reduced cast time from Fast Casting then cut in half?

I looked on both wikis' Fast Casting pages and didn't see the answer.

Thanks for the help & Cheers!
Luny

EDIT - Oops, guess I should read entire paragraphs. Thanks Xenex. So does "cumulative" mean you have a chance to get 50% off the ~66% cast time and wind up with ~33% cast time?

Each rank reduces casting time by aproximately 4.73%. Note that this is multiplicative, rather than additive, so with 9 ranks of Fast Casting, casting time is reduced to roughly 66.1% (0.9559) rather than roughly 57.4% (1 - 9 × 0.0473). Fast Casting is cumulative with HCT.

On the fast casting page on wiki (the unofficial/better one).
So yes it stacks.

Thats a good question. I guess that FC stands once you get of the town on all spells so all your spells have X% less cast time . HCT triggers on chance when you cast so if your cast spell time is 1,70seg instead 2,5 you should cast on 0.85seg when you trigger HCT mod/insc ¿? . Not sure , hard to see it ingame but i think it stacks.

Test it with a stopwatch and Meteor Shower (or something similarly long casting.)

hct does stack with fast cast, hct is applied after fast casting.

Thanks for the replies. Glad to know there's not some sneaky hidden rule taking over like how dual hsr mods can't give quarter recharge.

yes it does. you can easily tell casting something like diversion.

Except that there's a cap on activation time, so I'd assume that if you have 15 or greater fast casting, it won't stack. (Cap is 50%)

^ No.

There's a cap on recharge time of 50%, not casting time. If what you said is true, 40/40 sets couldn't give you a cast in 1/4 time, which they can. Or for a PvE example, FC and Mindbender (50% faster cast) stack on top of each other.

I'd assume that it counts a 40/40 weapon set as one item. Otherwise, these items aren't counted for stacking purposes.

You're wrong.

Take a mesmer with Mindbender and Meteor Shower out to the Isle of the Nameless. With 13 Fast Casting, I get a "skill activating" bar telling me that I'm casting Meteor Shower. When I do it with Mindbender, it casts in just under 1.5 seconds without the activation bar - well under the 2.5 second cap you're claiming. It's also coming from two sources - FC and Mindbender.

Then I decided to throw in Stolen Speed, another -25% casting time modifier. It went down even more, and that's three sources stacking with each other.

If you don't have a mesmer, or at least not one with Mindbender, I'd be happy to show you in game. I'll be on for a while.