Slitherine

IF Undrilled Other moves less than its full move because terrain or friendly troops prevent further forward movement, do they have to pass a CMT for moving less than full distance?

Certainly if blocked by friends - by definition you are moving less than your full move.

Terrain is more complex as the terrain often reduces move distance. IIRC you have to move your full distance or pass the CMT (or have a general with you). However, I seem to recall there's a special case (say undrilled knights 3MU from difficult going) where you can stop at the edge if going into the terrain would drop your move too much.

When you reach thye terrain if you can't go any further you have moved your full move, so If HF reach difficult after 2.5 MU they have moved a full move as actuelly going into the terrain limits their move to as far as they have gone.