A new deadlock-free adaptive routing algorithm is proposed for n-dimensional meshes with only two virtual channels, where a virtual channel can be shared by two consecutive planes without any cyclic channel dependency. A message is routed along a series of planes. The proposed planar adaptive routing algorithm is enhanced to a fully adaptive routing version for 3-dimensional meshes using the idle virtual channels along the last dimension. Another deadlock avoidance technique is proposed for 3- dimensional meshes using a new virtual network partitioning scheme with only two virtual channels. Two virtual networks can share some common virtual channel based on the virtual network partitioning scheme. The deadlock-free adaptive routing scheme is then modified to a deadlock-free adaptive fault-tolerant routing scheme based on a planarly constructed MCC fault model. Sufficient simulation results are presented to demonstrate the effectiveness of the proposed algorithm.