Randomness & Probability in Games
Why Didn't I Get the Rare Drop?!
Why Didn't I Get the Rare Drop?!
When you roll dice in a game, is it truly random? Computers can't actually be random - they use math formulas to create numbers that look random. This is called pseudo-random (fake random). Click to see how!
Unpredictable, like radioactive decay or atmospheric noise
Calculated from a formula - predictable if you know the seed!
Computers use algorithms like the "Mersenne Twister" to generate billions of pseudo-random numbers before the pattern repeats. For games, this is random enough!
Every pseudo-random sequence starts with a seed number. The same seed always produces the same "random" sequence! This is how Minecraft generates the same world from a world seed.
Minecraft seeds create identical worlds because the same seed gives the same random numbers for terrain, caves, and structures.
Speedrunners use specific seeds to get favorable random events, like finding diamonds quickly.
A single die has uniform distribution - each face has equal 1/6 chance. But when you roll two dice and add them, something interesting happens: 7 is the most likely sum! Why? There are 6 ways to make 7 (1+6, 2+5, 3+4...) but only 1 way to make 2 or 12. Roll and watch the pattern emerge!
2: 1 way | 3: 2 ways | 4: 3 ways | 5: 4 ways | 6: 5 ways | 7: 6 ways | 8: 5 ways | 9: 4 ways | 10: 3 ways | 11: 2 ways | 12: 1 way
This triangular shape is a probability distribution. Casino games like Craps use this - betting on 7 is smart, betting on 2 or 12 is risky!
Roll a die 10 times and you might get weird results. Roll it 10,000 times and every number appears almost equally! This is the Law of Large Numbers. Watch how the distribution evens out!
Casinos rely on this law! Individual players might win, but over millions of bets, the house always gets their statistical edge.
Not all random outcomes are equal! Games often use weighted randomness where some results are more likely than others. Adjust the weights below!
Games use loot tables to determine what drops from enemies and chests. Each item has a "weight" - higher weight means more likely to drop!
| Item | Rarity | Weight | Drop Chance |
|---|---|---|---|
| 🪙 Copper Coin | Common | 50 | 50% |
| ⚔ Iron Sword | Uncommon | 25 | 25% |
| 💍 Ruby Ring | Rare | 15 | 15% |
| 💜 Epic Armor | Epic | 8 | 8% |
| 🔥 Dragon Slayer | Legendary | 2 | 2% |
Total weight = 100. Roll 1-100. If roll <= 50, copper. If roll <= 75, sword. And so on!
Many mobile games use similar systems but with legendary rates as low as 0.5%!
Pure randomness can feel unfair - you might never get the rare item! Many games use pity systems that guarantee a rare drop after X attempts. Watch the pity counter fill up!
Many games also use "soft pity" where the chance gradually increases as you approach the guarantee. In Genshin Impact, rates jump from 0.6% to ~30% after 75 pulls!
Ever play Tetris and get 5 S-pieces in a row? Modern Tetris uses a shuffle bag - all 7 pieces go in a bag, you draw until empty, then refill. This prevents cruel streaks!
Could get same piece 7 times in a row (1 in 823,543 chance)
Maximum gap between same pieces is 12. Much fairer!
Many games have abilities with a "% chance" to trigger. But how does the game decide? It rolls a random number 0-100 and checks if it's under your crit chance!
Now it's your turn! Create a custom loot table with your own items and weights. Test it out and see if the drops match your expectations!
You've uncovered the secrets behind game randomness! From pseudo-random algorithms to pity systems, you now understand how developers create fair (and unfair) odds.
Computers use formulas, not true randomness
Same seed = same "random" sequence (like Minecraft worlds)
Given enough rolls, all outcomes balance out
Some outcomes can be more likely than others
Guarantees prevent infinite bad luck
Controlled randomness prevents cruel streaks
Put your new knowledge into practice!