Hiya
Do you possess an actual copy of Empire III rules?
After getting them from the cupboard…
Skirmish combat occurs at the beginning of every tactical combat phase (which consists of IGOUGO "impulses"). It only occurs before the first impulse if the controlling player wants it and if there is no formed cavalry around.
Dice are rolled and then the following factors are applied: skirmish combat quality, cover, density, morale class.
Then the victory results table…Draw, Limited Vicotry, Victory, or Decisive Victory.
Then the winner can apply skirmish fire to formed units.
..now have headache and suffering bad flashbacks. Rules back in cupboard.