Video games are rife with randomness manipulation.

- X-Com 2 lies in favor of the playing when displaying a chance of hitting of 85% [ https://www.gamedeveloper.com/design/jake-solomon-explains-t... ]

- Baldur's Gate 3 "Karmic Dice" will prevent streaks of very high or lows rolls

- Tetris games doesn't use Math.random for piece distribution. Most modern Tetris (like Tetris Effect) uses Fischer-Yates with 7 pieces (in the community we call 7-bag) or 14 pieces (it avoids repetition "at the seam" of a bag). The Tetris game I like the most (Tetris the Grand Master) uses a history system (the chance of receiving a recently distributed piece is heavily reduced; it's less predictable than 7-bag). IIRC even classic NES Tetris has a repetition avoidance system.

I don't know if that's still the case (haven't played in more than three years), but Magic the Gathering Arena (digital version of the collectible card game) used to rig the opening hands to make them "more average".

This had consequences on competitive play; they wouldn't even tell you how exactly the algorithm worked, so the only way to build a deck was lots and lots of simulations.

There are also specific physical shuffling techniques used in physical magic the gathering games, in order to distribute mana more "evenly".

Yeah, but those are cheating, and it's not particularly easy to cheat in that specific way. In a high level match, whenever you shuffle your deck, your opponent can (and in fact is required to) also shuffle it, and they're the last to touch it.

Cheaters, like in any game, tend to look for methods that maximize the combination of impact and plausible deniability. Marked sleeves, sleight of hand (pun very much intended) etc.

It can also be used in friendly games, where everyone is aware of it.

there was a whole HN post about the Tetris RNG a few months back. I'm too lazy to search rn but it might be worth a read for others.

previously:

https://news.ycombinator.com/item?id=20872110 - Sep 2019 (41 comments)

https://news.ycombinator.com/item?id=37107346 - Aug 2023 (16 comments)

Jonathan Blow did a good talk on this, but unfortunately the only version of it I know of is concatenated by some youtube uploader with a silly twitch stream (also by Jonathan Blow, but less interesting, and not even sure he is correct about that particular game being rigged?) so just stop watching after the presentation: https://www.youtube.com/watch?v=l0KEDYFWbVc ("Explicit Lying" seems to be the title of the talk?)

A shuffled deck of cards is still random, even if the probabilities of each card draw aren't independent.

An easier solution is to not say e.g. "this attack has a 25% hit probability" but rather say "this attack will hit every 4th time".

Then you are not lying to the users, and your tooltips/docs etc. are correct as well.