You seem to think that randomness is dichotomic: either you can predict or it’s fair game.
That’s not exactly the case: a RNG (be it true or pseudo) can be unpredictable and still biased, i.e. you don’t get to know when a queen is next in a [constantly reshuffled] deck even if the deck has five queens.
We can concede that unpredictability is sufficient. Or not.
It would also be a sign of non-randomness. Randomness is typified by not being consistent.
Edit: HAH I just noticed the original post was from 2018. That player probably stopped playing long ago due to the inconsistent (non)randomness.
Bad analogy, the dice are an independent roll (and not as random as you think). A summons is part of a (pseudo-)random string generated server side.
Your point being, exactly?
PRNG outputs being non-independent?
Dicerolls being theoretically modelizable under the complete information assumption?
My point was that a randomly “chosen” subset (of adequate cardinality) of [in wide-sense] random events should exhibit the same stochastic properties of the full set of random events.
I.e. the fact I don’t see all the PRNG outputs is not relevant as long as I see enough outputs and we can assume I’m not shown outputs based on any bias.
Because we are assuming that, aren’t we? 
No, i did not. Random is random. It cannot be on two polar opposites as you have worded: dichotomic. If it predictable, then its not random anymore, right? And the game would suck since you dont need to solve the puzzle of the boards as you can win all the time in raids and in wars. Some people here think that the board is rigged and that everything that is supposed to be RNG-based is not allegedly random. Well, if they can just predict the tiles on every opening board, i will tend to agree with them. So far, none has attempted to present a clear and convincing evidence that the board is not random and they mostly state it based on their personal bias.
By the use of the word “can”, are you insinuating that the board is also predictable? If so, by all means, enlighten me, convince me? Have you already cracked the code? Did you already discovered a third-party app able to determine the opening boards, the numbers and positions of the tiles at the onset as well as to the resulting matches or cascades? I would love to learn that and perhaps join the hoard of tin-foil hatters claiming that the board is not truly random.
My wife plays a game advertised here in Mystic Vision, something to do with a vacationing butler about home and/or garden. And it has boards and missions that is so darn hard that even if i used her special tiles, i cant seem to be able to complete the board missions. And she is angry with me for depleting those special tiles.
As far as I know, RNG means random numbers generator. If it is predictable, then it cannot be random. Once a solid proof is proffered, that would be the time i may start my journey in weaning myself on this game.
Assuming the numbers are randomly generated on the server side and then randomly distributed amongst the player base, if there is any non-random skewing you need to consider all the results. A randomly “chosen” subset of adequate cardinality would require many thousands of results; for an individual that is months and months of data points.
Or individual accounts are being targeted in which case it has absolutely nothing to do with the RNG, and again requires thousands of data points.
As for your questions,
They are until the seed is changed. Hence “pseudo”.
They are. However, any complete information model must include the observer and thus is likely unachievable. The very act of observing changes the initial conditions. Nevertheless, dice rolls and coin flips (like the weather) are a poor example of random.
The ultimate problem with RNG is that it’s virtually impossible for any individual to be able to prove whether it is or isn’t working “properly”.
And even if thousands of people keep spreadsheet results on it and the overall results show that “yes, X percent of the time you get Y result,” that doesn’t mean that everyone is getting the same results. Some people might be beating the odds, while others are getting totally screwed.
Which brings us back to the original problem. Is SG intentionally screwing those people? Or is that just RNG?
Because in the real world, it’s not at all unusual for random chance to screw over random people for no reason while also ridiculously rewarding random people for no reason.
Take two unlikely opposite scenarios: winning the lottery vs. getting struck by lightning. The odds of either happening to any individual even one time are generally considered to be incredibly low. Yet, there have been multiple examples of people both (1) winning the lottery more than once, and also others of people (2) getting struck by lightning more than once.
As much as I would love to blame the game when I get a bad board or a bad pull, it’s probably just as likely that the universe itself has aligned against me.
EDIT / ADDITIONAL / assorted nonsense:
I wonder if I’m the only one who ever tried this. Have you ever played a coin flip game with yourself? Calling out what you think it will land on each time, compared to what it actually lands on, and tracking the results.
I have. And when I did, I made the wrong call over 70% of the time.
I was flipping the coin. I was making the calls. Obviously my calls are most likely to end badly.
So then I tried it again, only this time, I did the opposite of what I would normally do. If my instinct was to call heads, I would call tails instead.
Did it using that method, in the same number of flips. Again, I was wrong 70% of the time.
Which meant that my normal instincts would have actually been right 70% of the time in the second sample. But the coin decided to reverse itself just to spite me.
Absolutely not.
I’m saying that the fact you can’t predict results doesn’t mean a random phenomenon is working as it should.
That is a distortion.
A PRNG is predictable even if none of us can predict it.
Hence this point of discussion needs a deeper definition structure, otherwise it’s nonsense.
I know a thing or two about random, models and identification 
My questions were more or less rhetorical 
That’s great! When it comes to the forums here my default position has become that people don’t know anything about random.
Just another anecdotal fact to add to the “you hardly lose because of random” pool.
I just barely lost to this team
We can assume that’s bad luck.
But we can also assume that conceiving a skill that out of a diceroll - i.e. nothing the player can really do about it - can take away thousands of damage is poor design.
N.B. as per usual this was the first day I was playing in tournament because… because, really, enough of the very unlikely events already.
Especially when fighting dynamics take away the chances to stall and counter.
