An overview of recent progress in the theory of inertial confinement fusion (ICF) targets is presented. Work on traditional target schemes, based on the hydrodynamic mode of ignition, is reviewed only briefly, while most of the attention is devoted to the fast ignition approach. The general advantages of fast ignition are illustrated with a simple model for characteristic assembled fuel configurations. Special attention is paid to a newly proposed concept of a cylindrical reactor-size target, compressed and ignited (in the fast ignition mode) by two separate beams of very energetic (Ei ⪆ 0.5 GeV u−1) heavy ions.