Although not widely practiced anymore, "Chohei" was once a very traditional way for Ataiyan families to acquire wealth and military force. In the oldest days of Ataiyo, when affluence wasn't exactly in good supply, those noblemen who needed more guards but could not pay for them could, instead, have one of their pre-existing guards challenge the champion of a warrior house to a contest of wit and arms. The winner of these contests was determined by knockout, death, resignation or some other, predetermined condition; and the sponsor of the winning team got to collect on whatever terms the "Chohei" had been made under.
The practice was one of mutual agreement, so it was much like a voluntary bet with military force and money on the line. That said, refusing a "Chohei," even today, is traditionally considered dishonorable. Likewise, making unreasonable requests of the opposing team is also dishonorable.
While still kept alive in the codes of some families, "Chohei" has actually fallen out of favor among the majority simply because of the obscene amount of rules that accompanied it later in its lifespan. Nowadays, it's rare to see one such contest, but any "Chohei" is still considered a matter of importance and entertainment when it does occur.
-Ichirou Hattori, Ataiyan Scholar