This one probably needs a Japanese and Mahjong expert to decipher:

（３）全局を一ハン（飜）しばりとし、二ハン場とする。

This is the third rule about the basic game setup of (my version of) the official Japanese Mahjong Tournament rules. A 局 kyoku is one round, a ハン／飜 han is a type of multiplier used in scoring. So far so good, but I have no idea what this rule is trying to convey. There's no further context in the immediately preceding or following rules. Can somebody tell me what this means?