What is 'First Strike'?

[strhopper]

I think first strick is like the archer in civ 3

 

[Alphidius]

Maybe "First Strike" means that the attacking unit deals out damage before melee starts. It would dish out the first set of damage before normal combat.

Then of course there would be "First Strike Immunity" or "Negate First Strike" ability which counters the "First Strike" ability...

 

[Crayton]

Two units with an equal number of 'First Strikes' negate each-other.