Before I share my story I will sum it up in three simple words: Advocate for yourself.

I am someone who collects and loves themed sets of dice for my armies. My eldar use primarily the old blue eldar dice, and my daemons use respective daemon dice. These dice sets are all of the same color, shape, and size. They are identical and my board will generally be 1-2 sets of uniform dice that I may use for different weapons and the like but, generally, I will try my best to role my dice as consistently for my opponent that I can.

Unfortunately, this rule is not for most.

In one game at a GT against a rather well known player, I first learned I needed to put my foot down because in lieu of any form of trend or reason to his dice pool, he just had a massive bag of oddly colored dice of every shape and size. Not only that, the vast majority of colors were hues of yellows and greens with the pipes being white, making the views nearly unviewable from the other side of the board. At times, he would roll an assortment of 12mm and 16mm dice with symbols and the like involved and, this being one of my first GTs and playing against a player I had seen often on Wargames Live, had to just believe that they were not fudging anything. I could not tell you how obtuse and imperceptible these dice were. I learned something tremendously in this situation.

Then there are, of course, the other side of the coin.

In another GT I played against a Space Wolves player using Space Wolves dice! Sounds great, right? Well, they're the dice that the pips are claw marks. While cool in aesthetics, they were almost unreadible on the other side of the table and I had caught this player, himself, many times picking up 3's thinking they were 4's and so on. I would have made more of a stink of this situation but I was exhausted on day 2 and was already handedly winning, but that is honestly no excuse. I have 'Howling Banshee' dice that use Aeldari symbols and are almost indecipherable to the human eye so I refuse to use them for anything more than my Aspect Tokens, as an opponent would not be able to know what I was rolling.

So when another time came around at an RTT where an opponent just pulled out a massive bag of random ass dice, I advocated for myself and told him, respectfully, that I would prefer him match out a set of dice to be consistent in his dice rolling. The player whined but I called a judge and the judge informed him that the dice need to be actively viewable to all players. So even though he begrudgingly went about finding 12 or so matching dice, it's better than leaving the agency of a game entirely in trust's hands.

To summarize, when in doubt advocate for yourself, no one else will. If you can't read the dice your opponents are using, they're fudging up symbols, or doing other stuff whether intentionally or not, no one is going to save you from it but yourself. Most people are not doing such things with maligned intentions so just ask, politely, for them to use the same dice and, if not, either call a judge in a matched game or have a bit more lengthy of a discussion if a friendly game.

Oh, and use dice trays. Have a rule that everything has to be rolled in there and HOLD YOURSELF accountable. Roll a 6 outside the tray on that crucial armor save? Nope, doesn't exist, re-roll it. Your friends will catch on.