Are the dice rigged?
No. Here is how Armagammon rolls the dice, and how you can check it yourself.
Arma does not roll the dice. Arma, the engine that plays against you, is a separate program from the app. The app rolls the dice for both players in exactly the same way, and Arma learns each roll only when it lands, just like you. When it decides whether to double, the next roll does not even exist yet.
Every number is equally likely. The dice come from your computer’s cryptographic random number generator, the same kind used to create security keys, and we have checked the results statistically over tens of millions of rolls.
You can roll your own dice. In Settings → Gameplay, turn on Enter dice manually and use real dice at the table. Arma plays exactly the same way.
So why does it sometimes feel otherwise? Partly because strong play is about leaving yourself more good numbers: when Arma seems to roll exactly what it needs, it has often made sure that many rolls would do. And partly because one painful roll is remembered for years, while hundreds of ordinary ones are easily forgotten.