From Table To Screen: How To Be Random Without Dice

Today we’re going to look behind the curtain at the actual process of turning a board game into a video game. Specifically, we’re going to talk about dice.

These lovable little blocks are known to players of games far and wide. They’ve arguably existed for at least 4,000 years. Their purpose has been to add random elements. It is simple enough: roll the die, see the number. A different experience than simply selecting one yourself.

The fun in making a computer game is that this simple tool is not available. Computers are what we call deterministic systems. They can only follow specific rules to give any output. This makes generating a truly random number with them impossible. Thus, any time a board game asks for something as simple as rolling a die, a computer must do something entirely different.

Many systems generate a pseudo-random number based on an algorithm and seed. Since the computer is deterministic, the same seed will always result in the same number. This is usually done by using the system time of the computer itself, down to the millisecond or even nanosecond, to act as the seed when the random number is requested. This makes it virtually impossible for a human to get the exact same seed twice in a row on demand. Another method would be to use the output of something like a Xorshift algorithm, which maintains and transforms a bit state, to function as a seed.

The process doesn’t end at simply generating a number, however! Using the first number generated can limit player agency in a game and create frustration. When a player sees a 60% chance of success, even a small skew from the average can make it feel more like 20% chance even if it wasn’t. Some systems account for this by providing a ‘player advantage’, such as generating two numbers and using the one more favorable to the player.

Thus, when working with dice rolls in an adaptation like this, we have to account for not only how we make a pseudo-random number, but also how that end result feels to the players themselves. In our case, we chose to not implement any form of player advantage to more closely mirror the actual experience of rolling dice at the table. This may make the game harder than some players expect, but it will make all of your victories truly the sweeter while providing a more authentic experience.

If you think you can make a plan that overcomes the vagaries of chance, join us in telling your story in Eldritch Horror: Digital Edition.