Forgive the obvious Newbie tell here, but is there a generally agreed upon definition of a "Special"?   I can't determine if it is act related, or time related, or both.  I am very new to this, but would like to get a little more info before I start calling.  Any providers or experienced hobbyists  that can assist are appreciated!

If its not spelled out in the ad or TER post, a special is usually a discount on the time. Either a lower price of the normal session  or additional time for free. TBH, I don't think I can ever recall where a special was a certain act.  I don't like it when the ad says call for specials,  I prefer the "special" to be spelled out right in the ad, I don't like inquiring about prices, be it a normal rate or a special before a date. But that's just me.

typically a Special is a reduced rate offering.  It can include all activities or be restricted like a BJ.  More often it is for a lesser period of time...  as in:  "Special 100".  If her 1/2 hour rate is say 150, she is giving you a 50 break.  
But you want the whole hour, the price didn't change for that.  I once made the mistake of signing on for a Special...  turned out to be 20 minutes.  Fortunately she was willing to convert to full hour...  but in other cases, she might have bookings right after yours.  
One might inquire about Specials but ask if they are all inclusive & what the time interval is.
skb

it's an advertising ploy to get your attention, at least in my area, that's how I view it.  I see it constantly on backpage ads, usually offering some kind of discounted rate.  The thing is, if you don't know her normal rate, how do you know you're really getting a deal?  You don't......  In most of the bp ads I look at, the providers do not have websites, just their ads, and if they don't post a rate in the ad, again, you don't know if you're really getting a 'special'.....

It probably does not involve specific acts either, maybe instead of a discounted rate, more time for usual rate.  Less time for less money is also a possibility, if you are interested in a quickie of some kind.  Since you are paying for her time, I think it would be OK to ask her what the special is, just do not mention any sex acts during your inquiry.

These are just speculations on my part, 'special' could mean anything, but I think the main thing is to get your attention.  Best advice, be careful.  Do your research.  Look for reviews and read them.  Verify her pictures with tineye or google search.  Don't get in a hurry just because you think she's a real hottie and you're gonna get a great deal.

Swim

...unexpected expense comes up and they have to raise cash in a hurry.  Recently on TER, someone was offering specials as low as $40. to help raise rent money.

Can't be any more honest with you babe. Swim, Shoulda and Hidden are right on target with the various definitions of a "special." As a newbie, I am sure you are looking for a particular experience, that's what  brought you into this world! So, instead of selling your dream short, take your time, do your research and spend an hour or more indulging with a lady. A "special" may surely be a disappointing experience for you. She basically could be a B&S or needs to get her cash up to pay a bill and could care less about you or if you're happy. Good Luck!

A special does not necessarily mean buyer beware.There are many ladies who offer specials who are well-reviewed and reputable.I have offered specials in the past.Specials are usually a discount off what her normal rate is or additional time for free.I never seen a Special for any certain acts just off the provider's rate or additional free time if you book a certain amount of time.
For instance,if a lady's rate is 300/hr she might be offering a special of 200 or 250/hr instead of 300.
I offer specials to P411/Date-Check members that book multi-hour appointments.I do agree with Swim there is no way to know what the specials are unless she has her regular rates posted and then her special rates posed in her ads and/or website.When I do offer specials I always have my regular rates posted and the specials underneath.If this is not posted there is no way to know if you are indeed getting a special or is the lady just trying to draw attention to her ad.Regardless,if a lady is offering specials or not you need to do your research google her info and see if she has reviews here or another site.
Good luck to you!

And I'm sure many other quality providers do the sameness you.  IMHO, if guys know they are really getting a 'special' deal, they will be more likely to go for it, I know I would.

Swim

a "BBBJ only" special when they are having their period.  The special is usually at a reduced, from their FS rate, price.

Another advertizing method is to offer additional time.  In other words, if you pay for an hour of a ladies time, she will add 30 minutes to your time without charging you more.