[wclass___]

Are they legal? (I think they are)
Why i can't find them in top pair cc?(too difficult? myb they dount need them?)

Here is one prism signal agreement:

http://users.tpg.com...fence/prism.htm

Sorry, if this issue has already beed examined several times, but i couldnt find the answers...

Hate Me

[FrancesHinden]

Without examining the merits of the method in detail, the example hand in the link you give is a poor example, as all that was needed to beat the contract was for partner to give a standard count signal at trick 1...

[ArtK78]

Encrypted signals are not legal in ACBL events, but Prism signals are not encrypted signals.

Unless someone can find a reason why Prism signals are not allowed, I would say they are legal.

[ASkolnick]

I am not sure they are legal in the GCC, not by the encrypted signals, but by the Dual Message carding are not allowed. Once could imply, knowing length in multiple suits, is considered 2 different things, but the ACBL is weird when it comes to this stuff.

[Echognome]

I seem to recall something in the letters to the editor section of either this month's acbl magazine or last month's where there was a question about prism signals and the editor wrote that they would be illegal. Maybe it was just illegal in GCC.

I tried them for "fun" for a short while about five years ago. They weren't that fun really and seemed to slow down play as you worked out all the possible distributions. You could sometimes have a full count on the hand very early, but of course you could also do so with count signals in general.

I imagine if they became popular, they would be more of an advantage for a good declarer than a good defender.