If you’ve spent any time with tabletop role-playing games (RPGs), you already know just how big a role randomness plays here. When a Dungeon Master rolls a d20, it determines everything: whether you can climb, swim, pick a lock, avoid a hit, or land a spell.
While a party sitting in someone’s basement can just use a d20 and call it a day, groups playing online have to rely on computer-created options issued by random number generators (RNGs). Many DMs also use these tools to prepare campaigns and come up with names or encounters.
But do they really work the way we think?
The Definition of Random
To determine whether computer-based RNG tools can produce truly random results, we should first define what “random” actually means.
Namely, for a result to be genuinely random, you must be unable to calculate or predict it in advance. RNG systems that are used in everything from video games like Minecraft to catalogues like https://fortunesultimateslots.com/ apply that exact idea.
However, computer-generated randomness isn’t the same as that of a physical d20 die, where each face has the same 1/20 chance of landing on every roll.
How Computers Actually Generate Randomness
Your PC is a deterministic machine. If you give it a starting point and instruct it to do something from there, the result will always be the same. As such, computers can never really generate anything genuinely random.
That’s why most RNGs are actually pseudo-random, or PRNGs for short. They’re also called deterministic random bit generators (DRBGs).
These tools apply mathematical algorithms to an initial value (seed), producing random-looking results. But because the process is still deterministic, you can reproduce that same sequence of numbers as long as you know the seed. That alone means the outcome isn’t truly random.
The Role of Seeds in RNGs
Minecraft world seeds are a prime example of this in practice. As a procedurally generated game, Minecraft relies on seeds to determine everything from terrain and biomes to villages and caves. So, when a player wants to try and set a new world record, they’ll first find seeds that generate everything they need nearby.
But outside Minecraft, a guessable seed can be problematic, since it essentially lets someone reverse-engineer the “random” number sequence.
How Modern RNGs Fix the Problem
To avoid “hackable” number sequences, modern RNG systems pull seeds from constantly changing sources, such as hardware noise, CPU background operations, or the millisecond-level system clock timestamps.
For instance, random.org relies on atmospheric noise to generate results. Millions of variations are at play here, ensuring no human or machine can use the seed to reproduce the number sequence or predict results in a game that relies on this system.
Another interesting example involves lava lamps. Yes, you’ve read that right: Cloudflare relies on 100 lava lamps on one of the walls in its headquarters, which the camera takes photos of regularly. Since the “lava” never takes the same shape twice, observing 100 of them at a time and translating photos of the wall creates randomness that’s used to encrypt data.
Final Thoughts
Most RNG systems don’t actually produce random results. Computers rely on deterministic algorithms, which automatically means the number sequences they generate aren’t necessarily random, even if they do look the part. As both random.org and Cloudflare show, true randomness has to come from something physical.
But for tabletop game enthusiasts, the practical takeaway is much simpler. Computer-based RNG tools can easily replace a physical twenty-faced die (or any other type of die, for that matter). So if you’ve been holding off on some Dungeons & Dragons just because you can’t set up a physical meet-up, a virtual tabletop is always an option.