Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

What does randomness look like?

empiricalzeal.com

Post reply on HN
Print view View original

91–100 of 123 posts

Re: What does randomness look like?

#91

Post by andrewcooke »

Xcelerate wrote: post #63

Here's a weird thing about randomness that has always bothered me: In quantum mechanics, if you measure two incompatible observables (like position and momentum) of a system, and then repeat that experiment many times, you will get two lists of real numbers. QM says you can predict the distribution of these numbers, but you cannot predict the individual numbers themselves. The popular way of thinking nowadays is that…

how do you expect to implement the "as-yet-undiscovered pseudorandom number generator" without any state ("hidden variables")?

Re: What does randomness look like?

#92

Post by wfn »

Avshalom wrote: post #88

As a side note this is one of those things that several tetris-clones deal have to deal with, long runs are probable but can frustrate a player so a lot of the times you want to to extra logic to keep it from being actually random. A uniform "deck" a couple times larger than the number of pieces is the usual suggestion prevents large runs and makes sure that you see every piece more regularly.

Marginally related --

on the other hand, here's "Evil Tetris": http://qntm.org/hatetris

Re: What does randomness look like?

#93

Post by zanny »

henrikschroder wrote: post #23
thurn wrote: post #14

Earlier quoted context omitted.

This is actually an important lesson for game designers. Real randomness is very frustrating for players! Games should be designed to not be random. For example, there's an expansion to The Settlers of Catan that lets you use cards instead of dice to ensure a nice smooth distribution of resources... I think it's a lot more fun!

Oh yes. Our intuition is that random is fair and uniform, but it's absolutely not. I was bit by another random quirk in World of Warcraft. There was a long-running achievement called "What a Strange Long Journey it has Been", which took at least a year in real-time to complete, and you had to actively play during each of the ten or so in-game festivals and holidays, and do some quests and tasks during each. If you mi…

As a completer of the "what a long strange trip its been" ( http://www.wowhead.com/achievement=2144/what-a-long-strange-... ), fuck Halloween.

A little randomness is good, it keeps the experience from being monotonous, but there is a balance between uncontrollable and unpredictable annoyance and quirky interesting outlier behavior. A lot of why WoW did so well was because it often walked the fine line, and it did it everywhere. In that game crafting had percent chances of giving skillups, you had to level weapon skills with a percent chance per hit of getting a point, you had critical % chance, hit % chance, dodge %, parry %, block %, you had talents that gave you % procs for special effects. Tremendous amounts of RNG that most people never even noticed but kept them playing for so long in many respects.

Re: What does randomness look like?

#94

Post by Too »

henrikschroder wrote: post #11

Back in the day I was in a raiding guild in World of Warcraft. And back then, each boss monster in a raid dungeon had a loot table, and when you killed it, your raid got a few pieces of random loot. And I don't know how many times I, and the other guy in the guild who understood statistics, had to explain to the others that random doesn't mean uniform. If a certain piece of armour has a 1/X chance to drop from a boss…

That's interesting, because in WarCraft 3, by Blizzard, randomness is designed to be "fair". They use a special word for it but i can't remember it at the moment.

For example, there are certain items that can give you a chance to blow a "critical hit", a critical hit multiplies your damage with X.

Say an item gives you 30% chance to do 2X damage. However, the randomness has memory and is designed to distribute the critical hits evenly by gradually increasing the probability for every non critical hit and resetting it for every critical hit. So the first time you hit the chance isn't actually 30% but more like 10%. If you miss 3 times the chance of the fourth hit being a critical is more like 40-50%. The hit after that will be back on 10% probability. (Just picking numbers out of the blue to illustrate the concept, I'm sure there's some more thought through math behind it)

As the nr of hits goes towards infinity, 30% of them will still be critical but the chance of getting streaks of non-critical or streaks of critical hits is very low.

In practice it works very well from my experience. It is however not completely exploit-proof, you could for example go and increase your probability of initially blowing a critical hit by first making a few hits on NPCs and then go to battle against a harder enemy. But that's more of a hypothetical exploit as the time and risk of doing this simply isn't worth those few extra percent.

Re: What does randomness look like?

#95

Post by Too »

Too wrote: post #94
henrikschroder wrote: post #11

Back in the day I was in a raiding guild in World of Warcraft. And back then, each boss monster in a raid dungeon had a loot table, and when you killed it, your raid got a few pieces of random loot. And I don't know how many times I, and the other guy in the guild who understood statistics, had to explain to the others that random doesn't mean uniform. If a certain piece of armour has a 1/X chance to drop from a boss…

That's interesting, because in WarCraft 3, by Blizzard, randomness is designed to be "fair". They use a special word for it but i can't remember it at the moment. For example, there are certain items that can give you a chance to blow a "critical hit" , a critical hit multiplies your damage with X. Say an item gives you 30% chance to do 2X damage. However, the randomness has memory and is designed to distribute the c…

I guess applying this concept on item drops available to every player on a whole MMO-server isn't as simple/fair as remembering the outcome of hits for a single player.

Re: What does randomness look like?

#96

Post by nostrademons »

michaelochurch wrote: post #53
chimeracoder wrote: post #45

Earlier quoted context omitted.

> This reminds me of Magic: the Gathering and the misery of mana screw. Incidentally, apparently people complain about the online versions of the game providing a land distribution that's "too even". Also, while mana screw sucks, between the fact that you can decide whether or not to begin with a certain opening hand and the fact that you can design your deck around such circumstances (mana fixing, proper distributio…

Incidentally, apparently people complain about the online versions of the game providing a land distribution that's "too even". Online bridge has a similar problem. Four riffle shuffles (which does not fully randomize hands) is typical in bridge games, and this means that long suits (and, thus, better hands) are more common. Early online bridge games randomized hands fully and therefore delivered crappier (flatter) h…

Eh, you'd design your deck around low-mana-cost cards, figuring that most of it had to work with 2-3 lands and the higher-casting-cost cards had to be used sparingly.

One of my favorite decks was an all-common blue/red control deck with 28 land, made so that I could bring it into school and not worry about it getting stolen. It was maddening to play against - I'd be like "Okay, I'll flood 3 of your creatures, block your knight with my clay statue, and counterspell your disenchant." Typically games would run 40 turns with nobody doing any damage, and then all of a sudden I'd be like "...and I'll Lava Burst you for 20. Game over." Or the Storm Shaman would come out around turn 10, by that time it's 5/4 and I've got enough mana to counterspell any attempts to remove it, and the game is over in 4 turns. Land can be devastatingly effective with cards made to take advantage of it.

Re: What does randomness look like?

#97

Post by michaelochurch »

heyitsnick wrote: post #85
michaelochurch wrote: post #53

Earlier quoted context omitted.

Incidentally, apparently people complain about the online versions of the game providing a land distribution that's "too even". Online bridge has a similar problem. Four riffle shuffles (which does not fully randomize hands) is typical in bridge games, and this means that long suits (and, thus, better hands) are more common. Early online bridge games randomized hands fully and therefore delivered crappier (flatter) h…

> Early online bridge games randomized hands fully and therefore delivered crappier (flatter) hands than people were typically used to. Are you saying that all online bridge games today do not fully randomize the shuffle, but simulate riffle shuffles instead?

I don't know exactly how they model shuffling, but I know that some players dislike truly random hands, which is why it's considered improper and impolite to do more than 4 shuffles.

This may actually be somewhat of a myth. I haven't verified it myself. I do know that Bridge protocol is 4 riffle shuffles, and typical riffle shuffles don't have enough entropy for 4 of them to randomize the deck (52! ~ 2^225.6, so you'd need 56.4 bits for each, and riffle shuffles have about 30 bits) but I find it hard to envision why this (possibly slight) lack of randomness would manifest itself in higher frequencies of good hands.

Re: What does randomness look like?

#98

Post by sp332 »

pfortuny wrote: post #84
Xcelerate wrote: post #63

Here's a weird thing about randomness that has always bothered me: In quantum mechanics, if you measure two incompatible observables (like position and momentum) of a system, and then repeat that experiment many times, you will get two lists of real numbers. QM says you can predict the distribution of these numbers, but you cannot predict the individual numbers themselves. The popular way of thinking nowadays is that…

Yes, that is the thing: Bell's inequality has been verified experimentally and that leads to a non-hidden variables reality (for the usual meaning of 'reality'): http://en.wikipedia.org/wiki/Bell%27s_theorem

Even weirder http://arstechnica.com/science/2012/04/decision-to-entangle-...

Re: What does randomness look like?

#99

Post by chimeracoder »

nostrademons wrote: post #96
michaelochurch wrote: post #53

Earlier quoted context omitted.

Incidentally, apparently people complain about the online versions of the game providing a land distribution that's "too even". Online bridge has a similar problem. Four riffle shuffles (which does not fully randomize hands) is typical in bridge games, and this means that long suits (and, thus, better hands) are more common. Early online bridge games randomized hands fully and therefore delivered crappier (flatter) h…

Eh, you'd design your deck around low-mana-cost cards, figuring that most of it had to work with 2-3 lands and the higher-casting-cost cards had to be used sparingly. One of my favorite decks was an all-common blue/red control deck with 28 land, made so that I could bring it into school and not worry about it getting stolen. It was maddening to play against - I'd be like "Okay, I'll flood 3 of your creatures, block y…

> Land can be devastatingly effective with cards made to take advantage of it.

One of my favorite decks is loosely based on a 5-color preconstructed deck from the Apocalypse era - it's basically almost all mana fixing, with a few cards that take advantage of multiple colors, and then four "Life/Death"s[1]

All that time you spent doing nothing but playing land-generating spells suddenly pays off when you can attack with twenty 1/1 creatures in a single turn, then declare them unblockable[2] and rinse and repeat the next turn[3].

It's even better because land-destruction spells are much rarer (and more costly), so you're impervious to Wrath-of-God[4]-eque spells.

[1]http://gatherer.wizards.com/pages/card/Details.aspx?multiver...

[2]http://gatherer.wizards.com/pages/card/Details.aspx?multiver...

[3] If, by some miracle, they had enough life to survive, that is.

[4] http://gatherer.wizards.com/Pages/Card/Details.aspx?multiver...

Re: What does randomness look like?

#100

Post by unconed »

michaelochurch wrote: post #36
thurn wrote: post #14

Earlier quoted context omitted.

This is actually an important lesson for game designers. Real randomness is very frustrating for players! Games should be designed to not be random. For example, there's an expansion to The Settlers of Catan that lets you use cards instead of dice to ensure a nice smooth distribution of resources... I think it's a lot more fun!

Real randomness is very frustrating for players! Games should be designed to not be random. This reminds me of Magic: the Gathering and the misery of mana screw. I disagree with the uniform "should be", because there are so many different design objectives. Slot machines aren't "good games" by Euro standards, but people spend a lot of money on them. (One can argue about whether that's enjoyment or addiction. I'll ski…

The thing about slot machines though, aside from the fact that the pay outs are not uniformly random, is that they're designed to have tons of almost-wins, i.e. "bar bar cherry". You think you're "so close" to having won that you think if you just try a couple times more, you'll really get it. This goes so far as to program the motors for the wheels to have a specific wobble, so they flip over from a winning combo to a losing one at the last second.
Post reply on HN