Dark Omen fear

The following notes are made based on in-game observation and play-tests:

• when unit with fear charges enemy unit it has to make Ld test and flee if test failed
• if charged unit fails fear Ld test it starts retreating instantly and cries "We are terrified" in comparison when unit charged in flank/rear it starts retreating after contact with enemy and cries "Retreat"
• fear ability only works when unit with fear outnumbers enemy unit ^₁ (but not when unit shouts "We fear the enemy" in melee)
• if both rival units have Fear/Terror ability then it is disregarded
• fear spells affect unit with fear\terror ability but don't unit with immune to fear ability. Unit affected with the fear spell and failed LD test shouts "Retreat" before fleeing while "We are terrified" if falied LD test provoked by charging enemy with Fear or Terror ability
• it is uncertain if fear works in the following melee rounds after initial one but in WHedit there is an ability that cause fear on damage 
• Unit shouts "We fear the enemy" when:
  • enemy has fear|terror ability (disregarding number of enemy models, i.e. even with 1 model)
  • it charges enemy and not vice versa
  • it collides with enemy after charge and fails Ld test  (before the first melee round starts and never in the following rounds)

It is uncertain what exactly happens when unit shouts - "We fear the enemy!" during melee combat. But as an assumption, unit that charges or gets charged by feared enemy, fails its Ld test and needs to roll 6 for all its strikes in the first combat round 

Unit may also shout - "We are terrified". It most likely is related to Terror ability but its effect in DO is unknown for now.  Playtests confirm that it happens when unit fails LD test to enemy unit charge which posses Fear or Terror abilities.

Formula for the Fear test is the same as for any other Ld test

if Ld >= randbetween (1,12) - test passed
else - test failed

from DO Manual:

If a regiment comes up against an enemy they fear, they might automatically rout across the battlefield just to get away from their foe! Similarly, if a regiment encounters an enemy they hate, they will need no second invitation to engage in battle. If a race is immune to fear and hatred then it goes without saying that they will be much harder to rout off the battlefield!

The relative strength of the enemy regiment has an effect on whether the fear is enough to deter your regiment from engaging them in battle. For example, one solitary zombie probably isn't going to be enough to make your sixteen man strong Cavalry regiment flee in fear! They will still fear the creature, but not to the point where they feel the need to run away from it.