The following is a procedure for quadrupling-down. It is legal in Atlantic City according to the judgements reached in the notorious "Campione" case. Other jurisdictions, particulary other states, may have differing laws, though I suspect the AC precedent would have some influence.In jurisdictions such as Britain, where casino rules are set by the state and posted this procedure would be illegal. The author does not advocate its use in any circumstances: it is likely to get you barred swiftly.
.A player at third base doubles down and turns up his cards while the dealer is looking at first base. He says to the dealer "I want to double. I just get one card don't I?" and points to the already-doubled stack. He is saying that he wants to double and has already put out the extra chips, which he is making the dealer aware of by gesture. Nowhere is the rule posted that the double-down stack goes besides the original. He then confirms that in this casino he gets just one more card.
At no time does the player commit fraud by misrepresenting himself or violate a posted rule.
If the dealer is not alert he will say "you must put out your extra chips beside your stack".
The player then says "So you want me to put more chips besides the ones I have already put in the circle, then you are going to give me one card . If I lose, I lose all the chips there. If I win, I win chips equal to all I have there."
If the dealer is not alert he will say "Exactly".
The player has made a proposition to the casino which has been accepted by the casino representative, the dealer, that the rules be changed. It is the same as asking for the table limits to be raised.
The casino videotape will clearly show you questioning the dealer and gesturing as to what you are doing, while the dealer assents.