What responsibility do you owe your opponent regarding how you play the game?

One of the most memorable games I have ever played was a game of Horus Heresy, a Games Workshop boardgame written by Jervis Johnson. My opponent was Gary, my gaming buddy and long term nemesis. We had been playing lots of 40k and Blood Bowl and were getting jaded. For a change of pace we broke out the Horus Heresy boardgame.

Being a goody-two shoes Imperium-lover I played the Emperor while Gary explored his dark side by commanding Horus. It took an hour and fifteen minutes to set up the counters. It's not that we were particularly slow, it's just that sort of game.

We had just two hours left to re-enact the single greatest battle in the whole of humanity's history. Would history repeat itself, with the Emperor teleporting up to Horus' battlebarge in a desperate final gamble? Would Horus risk his life and the whole crusade by setting foot on holy Terra? We were about to find out.

The forces of Chaos had first turn.

Gary dropped Horus straight onto the Emperor's Palace. The best defended location on the map board. Hell, it's the best defended place in the entire Imperium. And Horus volunteers for the first drop pod.

Of course, the defenders shot up the pods as they came in and the Emperor smacked Horus upside out. The game ended after twenty minutes.

I was shell shocked. Was that it?

Even if Gary's audacious plan had worked, and Horus had killed the Emperor, the game would have been over in the first turn.

I felt no elation or sense of achievement in the win. My tactical acumen had not been tested. It was an entirely pointless waste of time. We didn't even have enough time to set the board up again, so our gaming night was over.

This recollection leads me to the point of this post and the following question.

What responsibility do you owe your opponent regarding how you play the game?

I'm asking this question now because I played a couple of games of Warhammer recently which made me question my own, and my opponent's, approach to the game. The first was played after a three week hiatus caused by my work commitments. Gary deployed his Dark Elves almost entirely within a third of his deployment zone with most avenues of approach blocked by a large wood on one side and rocky columns on the other.

His stated aim was to slow my units down as they came through the gap and let my own units get in my own way.

My initial thoughts were to refuse the bait, sit outside the terrain and play for the draw. But I'd waited three weeks for the game, I wanted to have a battle, not just shuffle a few units around, and besides, I was Chaos dammit! In the end I charged right in and was defeated. Gary congratulated himself on his superior tactics and I went away with a peculiar feeling of disenchantment.

In the following week's game Gary repeated the trick, deploying all but two units of his army inside the bend of a river. This time I refused the bait and simply destroyed the two units with my whole force then shuffled into the table quarters. I won a marginal victory, but I felt worse than I had done the week before. This time I had participated in this travesty of a game.

I was deeply unsatisfied. I felt that the 'unusual' deployment of my opponent had significantly affected my enjoyment of the game.

Did Gary really have some sort of moral obligation to consider how his play might impact upon me, though? Surely it is none of my business what my opponent does with his own army?

Does the context matter? Are the expectations different in a tournament versus a 'beer and pretzels' game? What if you play three times a week or only play once a month?

Let me know what you think.