
At the Congress of Vienna, offering. soliciting, and accepting bribes was considered a normal part of doing business diplomatically. Even statesmen at the highest level thought nothing of accepting "gifts," which could range in value into the millions of dollars in modern money.
There was, however, an accepted etiquette for such gifts, and those who violated that etiquette would find themselves roundly condemned. Since the occasion for the offer, solicitation, or acceptance of bribes may certainly arise during the game, it would be useful to lay out the conditions under which bribes may be taken or offered:
The cardinal rule of bribe-taking: One must never take a bribe to do something that undermines your nation's interests. Of course, it may very well be that a particular statesman may feel that a particular course of action is innocent, or even beneficial to his country, and take money to promote that point of view, while others in his government may disagree. On the successful negotiation of such gray areas are careers built.
Promises made in good faith should be carried out. Thus, it is considered extremely dishonorable to assure a petitioner that you will promote his cause in return for a certain consideration, and then fail to do so. However, it is considered perfectly acceptable to take money in return for "taking a matter under consideration" or "bringing the matter to His Majesty's attention", and then seeing the petition go nowhere, because the king, or the other ministers simply could not be brought around to a particular point of view. But these possibilities should be made reasonably clear. Again, there is a considerable gray area that talented and well-compensated statesmen navigate well.
Bribes do not necessarily need to take the form of cash. Cash is not necessarily considered gauche, but bejeweled watches, solid gold snuffboxes, sterling silver dinner services for twenty four, etc. possess a certain flair, and, if the petition is particularly delicate, may provide camouflage for the cause's champion. Bribes need not even take the form of mineral treasure. Many a beautiful woman has found that her favors are valued more highly than gold (and produce better results!)
So, over waltzing or whist, to not be shy about lubricating the wheels of diplomacy in your favor (assuming of course, you have something of value to offer...)