If a unit is charged by an enemy that it fears then it must take a test to see if can overcome that fear and carry on fighting. Test when the charge is declared and the unit is determined to be within its charge range.
If the test is passed, the unit can fight on as normal. If the unit fails its test and its Unit Strength happens to be lower than the charging enemy, it will flee.
If the unit fails its test but its Unit Strength is equal to or higher than the charging enemy's, it will fight on as normal but must roll 6s to score hits in the first turn of close combat.