The objective of this web session is to give an overview of these Cash Balance mechanisms and illustrate some interesting actuarial problems of the topic. In a first part, we will define the concept of CB and compare it with other pension schemes. We will present advantages and disadvantages for all the parties. We will look at the effect of introducing a legal minimum return in the system. The second part is devoted to more quantitative studies. First, we will develop some financial valuation issues induced by the technique. We will look also at preferences between CB and DC in terms of utility function as well for the sponsor as for the affiliates; we will show in particular that we can express the problem as the Nash equilibrium of a game between the sponsor and the affiliates.