There's an attitude of "the right way to play" when it comes to table top games. I don't mean knowing the rules and how to actually play. I'm talking about how to measure ranges (from the gun? the hull? the base? the crew?), how to determine cocked dice, how to use certain terrain features, and so forth. There's a simple way to resolve these issues, but it's not the way a lot of gamers seem to take. Granted, this simple way won't work well in a tournament situation, but any time you're playing a game of dice for an actual prize, there's going to be some upsets.
Most gaming groups have their own convention of determining how to know if a die is cracked, and of course they're all as ineffective as the next. Place a die on top of the suspected cocked die and if it falls of it needs to be re rolled. Obviously that method favors a steady hand and someone with more patience. Ruling everything that isn't completely flat on the table seems like a good method, but time consuming, and occasionally impossible considering how your table is flocked and set up for terrain. However, there's a really easy way that no one seems to do.
Be consistent. If you re-roll a die that is resting slightly on a models base, or leaning on a thin part of a terrain piece's base, then ro-roll all dice that end up that way. Most of the time, what leads to negative feelings towards dice rolling isn't that one time someone re-rolls a one into a six. That is only the spark that starts the fire. The kindling of that situation is all the times the player
didn't re-roll a die in the same position. If on one roll, the die lands against a model's base and is showing a one and the player re-rolls it into six, and on the next roll the die lands in the same spot but showing a six and they don't re-roll it, that's when the table flipping rage starts building. It's the inconsistency of what seems to be your opponent cherry picking the dice that he re-rolls. It's not always their fault, they might not realize they're doing it. Or maybe you're not paying attention to the times they re-roll their successes. But ultimately, it's an inconsistency, and it's something both sides should be aware of. Personally, I tend to try to not re-roll as much as possible. If its on a model's base, those are usually fine. If it's on a piece of flock on a weird angle, I let it go. This might not be what you do, nor should it be. What you do should be consistent; what ever it is.
This applies to nearly everything. Remember you're here to play a fun game with a friend, not prove that your plastic army men are better than his. Don't give anyone a reason to feel like they've been cheated. If you measure your range from the muzzle of your gun, then
always measure your range from the muzzle of your gun. If you measure from the large decorative base for your mortar, then
always measure to and from there, including for receiving shots. It doesn't matter what method you use, as long as you
always use it and don't cherry pick which every method fits you and then blame it on the 'vague rules'. It doesn't matter if the rules are vague, that doesn't mean you have to be.
Announcing your intent is as clear as you can get. Verbally tell your opponent, "I'm moving this squad into the woods." Of course then prove that you have the movement to do so. That way when a turn later something goes to shoot at them, and it's not quite clear if they're on the edge or in it, there is no confusion, because you declared your intent and both sides agreed that that was what is happening.
Of course there will be instances that none of this advice is possible to follow. There will be tense moments that rest upon a very small margin. In these cases, take a breath, step back from the game, remind yourself you're playing a game. If what is happening is so close that neither side can agree, just dice it. Or, if you're feeling like taking the moral high ground, give it to your opponent. If something is really close, often with short range shooting and such, and it looks like it might be, but you're not sure, just give your opponent the benefit of the doubt. Don't do something controversial that might lead to your opponent feeling cheated. You're here to play a game with a friend, not argue that 1/16th of an inch is over the base and that you should have short range.
With out going on for too long, the last topic I have is the negative feedback loop.
When you do something like claim that 1/16th of an inch is over the base, and your opponent says no, and you press the issue, all you're doing is initiating a negative feedback loop. Whether or not you were right, your opponent will be bitter about the experience, and is now more likely to do the same to you. Maybe instead of arguing over a 1/16th of an inch, he'll just re-roll a die that was cocked that he wouldn't have re-rolled before had the negative feedback loop not been started. Maybe in response to that, you'll feel cheated and start being inconsistent with how you measure to cherry pick your advantage. He'll see that and start using unclear and grey areas of the rules to get his advantage, and before you know it, you're both playing a completely rules accurate game but no one is having a good time and both feel cheated. Don't start it. If you feel cheated from something your opponent does, let it go. Take the moral highground, don't start the feedback loop.
No pictures in this one. Sometimes communities get so much bitterness and salt against each other that they forget these things. It's just a game.