The Legislation is quite simple, purporting to amend Civil Code section 1589.5 as follows:

(a) Any term in a contract of adhesion purporting to waive the right to join or consolidate claims, or to bring a claim as a representative member of a class or in a private attorney general capacity shall be deemed to lack the necessary consent to waive that right, and is void. (b) This section shall apply to contracts that are entered into on or after January 1, 2013.

A copy of the bill can be found here.