How did you do that?

Look totally perplexed, and say "I have absolutely no idea!

"Do it again"

I can't, I don't know how I did it in the first place,

or

(pass them the cards/coins etc, etc...)

I'll tell you what, you do it on me and I'll see if I can work it out from this side.

Or;

I'd LOVE to tell you how to do it but, I just don't want to

Mostly I just smile and let everyone ask their myriad of questions. Surely, they are just reflexive questions, but there are times when you need to get on with it, so...

"How did you do that?"
- Much better than last time, thank you!
- Same as the last trick, but this time I used a different method.
- I ask myself that same thing everytime!
----my favorite has already been posted..."can you keep a secret...so can I"

"Do that again!"
- You mean you weren't fooled enough the first time?
- OK, pick a card (and then I perform a different trick).
----my favorite to this one is posted by Nelly----

"How did you do that?"
"I read the instructions"

"Do that again!"

"Again? I'm lucky it worked the first time!"

To quote Dunninger "For those who believe, no explanation is necessary. For those who do not, none will ever suffice.

How did you do that? If they are of the opposite sex, say, will you marry me? After all I don't tell secrets to just anyone. It works for telemarketers to.

"I tell people that it is a result of not getting a date in high school.....just kidding though...I had one."

I usually say in a kidding way when they ask
How did you do that..... my reply.... Ask Victoria..... it's Victoria's Secret!

Goodtime Charlie

Do that again:

At my age, I'm lucky I can do it once! (double entendre...mature audiences only)

After two beers, I'm lucky I can do it once!

Why? What did I do wrong the first time?

It's always better the second time...and I'm not that good.

How'd you do that?

I don't know, it's never done that before

or

I don't know, it's never worked before

If you get lucky, and have one person using the;

"I know how you did that" line
and another using the
"How'd you do that" line

just say: ask him he seems to know all my tricks
or
ask him, he'll explain it to you.

I remember someone in the Café using this one(which I love).

"You've already seen that one, I've got one I think you'll like even better." And then continue your routine.

It is a great comeback, it's non offensive, and completely defuses the situation.
I believe FCPREACHER was the first person I heard use it.

Steve
zzz

Q: "How did you do that???"
A: "Do What?"

I often get asked to repeat stuff, and reset or not, it's bad to repeat... generally I just say something like "I'm not allowed to do it twice" or tell them the two rules of magic (didn't know about the land war in Asia one) but I just tend to say that if I tell, that they'll take my wand away, which lets me pull out my wand (a magicians wand, wooden, with brass ends) and do some routine where it can be used

Some really great stuff here. A couple of things I question though. I would never offer any spectator any props if they were already hostile…… ..it puts all the attention on him and he will be tempted to act out, there is no telling what he will do or say. I learned that the hard way. It was a hammer.

When someone is heckling, the crowd expects and wants you to take back control. This is for the mean heckler, not for people who are just asking questions.

Try this, stop what you are doing… ..just look at him say nothing…… (he says, what's the matter, no comebacks?) ………say nothing do nothing……… The time between his remarks will get longer…… and the remarks weaker…… The crowd at this point doesn’t know what is going to happen…… they will hang in there to see if this guy has crushed you…… you will see him get smaller and smaller and quieter…… once it is obvious that he is uncomfortable simply say “next time if you don’t want the attention don’t ask for it” and resume your routine. I have never seen them keep talking after this.

.........Jesse

Good one Jesse, That hurts. I like it

I like all the responses above, very creative. I use what is explained in one of the ellusionist videos where he answers " If you liked that let me show show this one" or I just smile and continue my routine.

"The second rule is; never get involved in a land war in Asia but the first is; never go up against a Sicilian when DEATH is on the line! " - The Princess Bride, one of the few movies that actually improves on the book.

"I know how you did that!"

My response; "What? You mean there's a trick to this? All these years I've been doing it the hard way!"

I often use the old Sid Lorraine line:

If you promise not to tell, I'll explain it:
When I move the doggleblatt toward the sittabrea and, unknown to you, slyly wamble the gudleypin, you are under the impression that the flapasiling and leffing are going to come with it. That's where you're entirely wrong. Actually, the back part that crosses the bilyn, enabling me to secretly remove the underparl and show both hands empty. Now don't tell anyone else ok?

Others:

"It's SCIENCE!"

Or

"You might be able to fool me with YOUR version...so keep it a secret and try it out on me later!"

More:
*A good magician never does the same trick
twice... and neither do I

* I only do these perplexing miracles once
to prevent the audience from going insane!

* I promised Sigfried and Roy I wouldn't do it
again, or they won't let me pet their kittens!

* Grampa always said, "Once is enough
if you do it right the first time!"

If it's a girl here's a great pick-up line:

Spec: HOW DID YOU DO THAT
Magi: Well, it's complicated, wanna discuss it over dinner?

If they ask you at dinner say a bunch of weird stuff untill they're confussed and just forget about it..

like....First you jigsaw a court spot and lift the pass of the cull. =) something like that

Q: How do you do that?

I Find that a smirk or grin really can add impact to the trick. But if I'm going to use a line I steal Rush Limbaughs "Talent on loan from God."

As for the Do it again, I usually try and bridge my effects. So I'll just say something or other like "Better yet, watch this." Or if I'm closing in on a routine or preformance, I'll just play it off like I'm running out of magical steam or something. I find that when I act the part of magic using power, people buy into it.

Can you make my wife disappear?

Ya. Just be yourself. (Mike Ammar)