Rout and Pursuit
A unit must make a rout test in the following situations.
1. The unit just lost a round of hand to hand combat.
2. The unit suffers casualties of 1/3 or more of its current numerical strength to shooting and/or psychic attack during a single turn.
3. As indicated elsewhere in the rules. For example, while breaking away from hand to hand combat.
4. Anytime at the GM's discretion.
That last bit is why I went through them all. Again, Rogue Trader assumes that having a Game Master adjudicating the game is the default. Of course Leadership is the characteristic used for Rout Tests, but there is an interesting note. The test is made on leader of the unit's characteristic - even if it is lower than the unit! It's hard to see when this would apply, but I could see designing a scenario where a unit is burdened by a less than heroic officer.
A unit failing its Leadership Test is immediately moved 4" (apparently regardless of the movement characteristic of the unit) away from the fight. In subsequent turns, routers are moved at double their normal rate during the movement phase. The victors will pursue to remain in contact unless the pass a Leadership Test not to do so. If their movement is sufficient to keep up with the routers, they will attack again in the hand to hand phase, and the routers are treated as WS1! If pursuers follow routers off the table, they may return on the roll of a 4+ in the same spot on subsequent turns.
As mentioned in an earlier post, models which have not fired and are not with 4" of an enemy model may make a reserve move. Again, I think it is probably better to simply allow a double move in the Movement phase under these same conditions. However, it is interesting to note that Routing troops within 4" of allies also prevent them making reserve moves.
Rogue Trader has four psychological conditions that affect troops - Confusion, Frenzy, Fear, and Hatred. All tests against these conditions are made using the Cool characteristic. These effects may be built into profiles of races or creatures and some weapons and equipment may trigger these as well. The results of a failed test can create quite a list of effects. For instance, units suffering from confusion have a -1 to hit with shooting and hand to hand, may not use psychic powers, move at half rate, may not be split, AND ignores further psychology tests.