We deal in this chapter with the first passage times \(\tau _x\) from level 0 to level x, known as the ladder times, ascending if \(x >0\) , descending if \(x<0\) . The sequences of phases \(\{\varphi (\tau _x): x \geq 0\}\) and \(\{\varphi (\tau _{-x}): x \geq 0\}\) are called the ladder processes, they are Markovian processes, and they play a fundamental role in the analysis of MMBMs. We proceed under three successive assumptions: In the first case, the volatility parameters \(\sigma _i\) are different from 0 for all phases i, the second case is about fluid flows, where \(\sigma _i = 0\) for all i, and finally we analyse the general case where we do not make any particular assumption about the volatility parameters, beyond the one made at the beginning of Sect. 1.12 .