We just got Tide of Iron at a sci-fi convention. I've never played a board game quite like this. My board game experience has been limited to Risk, Monopoly, etc (the wal-mart stuff). I and my children LOVE this game. We have one question, though. What is the 'proper' way to use opportunity fire? For example, let's say I have a machine gun squad on op-fire and my opponent picks up his squad and moves it his 4 spaces. I would assume it's up to me to announce that I'm taking an op-fire shot, right? When do you do this? After he's already moved his squad and I say "no, wait, I'm taking an op-fire shot 2 hexes back"? We're really kinda struggling with this as this is the one part of the game where an 'interruption' is necessary (that we've seen) by the opponent and as there can be several units in op-fire at any given time, is it up to me (in this case) to keep track of the line of sight of all of them for every move he makes ( would assume so, just checking )? Perhaps what might help us (being newbs as we are in this case) would be to have someone video a game (portion of a game would likely be sufficient) to ensure we're 'doing it right' (if there is a 'right', lol). Thank you all for your time.

When moving, the active player should move the activated unit one hex at the time, pausing long enough to allow the opponent to announce OP-fire. Line of sight is measured with either a string or a thin elastic band. It is often better to use the shadow of the string, so as to avoid moving units around. Announcing OP-fire against a unit entering a hex that is out of LOS, does not prevent OP-fire at a later point in that units movement, so you can interrupt and measure whenever you like. Sometimes your opponent mistakenly thinks he is out of LOS, and moves fast. I that case just ask him to return the unit to the hex you want to attack with OP-fire in.

twinvenus said:

At the time you put a unit into op-fire, you should have a good reason for doing so, which should involve determining the line of sight and the distance conditions for potential targets. So yes, you should be remembering this information as the game progresses and you watch as your opponent's units either move as you had hoped they would or not. And your opponent knowing their units are within an op-fire field of fire should move slowly enough that you have the chance to declare. If this is done, then once they've moved on, I would say it's too late to change one's mind, so no forcing them back (as information about their final destination would be compromised by a take back).

...and if they start in LOS but the first hex they move to puts them out of LOS - you DO NOT get OP fire. Only moving into a hex allows for OP fire not moving out of a hex.