Randomness in Casino Games


This article aims to provide a brief introduction to the manner in which randomness is manifest in casino game design, and how this randomness translates into the experience of players. Before diving into randomness from a design perspective, however, it’s worth dwelling briefly on what exactly we mean by the concept of randomness.

What Is Randomness?

Randomness is a tricky concept the more you think about it. It’s one of those terms that is often abundantly clear to us in common parlance, but when examined more closely remains vague in its definition. In a mathematical or scientific sense, randomness essentially equates to non-patterned, or non-predictable, meaning that for a random property or behaviour of a system we cannot know a priori how it will react given a certain input or stimulus.

Of course, determinists will argue that randomness is not a feature of the universe - rather, its assignation to a feature is simply the voluntarily given confession that we do not fully understand it. And indeed this is a commonly held view in general. For example, for a long time it could rightly have been argued that the movement of the heavenly bodies was random - after all, no one knew the laws governing their trajectories across the sky. Only now that we understand them and can map planetary movements, etc., can we claim that their movement is non-random.

Randomness Concepts in Casino Games

Taking this view also implies that things can be more or less random given how well we understand them. The weather is a great example - meteorological models can explain with greater or lesser accuracy whether it will rain or not in the coming days. Seeing randomness as quantifiable in this manner, at least to a certain extent, provides a good foundation for understanding randomness in casino games, in which it is usually bounded. Bounded randomness can be understood as a limit to the quantity of randomness present and defines the limits within which it operates. Rolling a six-sided die, for example, will yield a numerical value between 1 and 6, it will never yield a fraction, a negative number, nor a number greater than 6, etc.

Finally, an important distinction in the context of casino games is whether randomness occurs in input or output. The difference between the two was best described by Keith Burgun in a much celebrated blog post, and goes as follows. Input randomness occurs in scenarios in which a game presents a random or seemingly random set of circumstances in which a player must make some kind of strategic decision to the best of their abilities. Output randomness is rather where the randomness is not present in the presentation of the game state, but rather in the execution of the player’s decisions. This distinction might seem subtle, but it informs a great deal of casino game design and is explored below.

Input Randomness

Games with input randomness are often considered deeper or more complex. In casinos, these include games such as Blackjack and Poker where players are presented with a random hand of cards but must then continue to make strategic choices with how to play out and bet on that hand. While the decision horizon is shorter than in games in other contexts such as video or tabletop games, there is still an element of strategic choice required by players presented with input randomness. In short, it translates to - how can I make the most out of the situation with which I have been presented? While some situations, such as a 2-7 hand in Poker present a greater challenge than others, a skilled player might be able to salvage even such a raw deal into some kind of winnings.

Output Randomness

Output randomness, on the other hand, often makes a game feel more straightforward, light-weight and, perhaps as a consequence, even more exhilarating. Games such as Roulette or slots including Monopoly Live feature exclusively output randomness, as the game state is always fully known before making a move, but the outcome of that move is always random (although usually bounded in some manner). Take Roulette as an example - every game starts with the same set up and all parameters are clear to all players who are free to bet as they wish. However, after bets have been placed, the output of the game, that is the outcome of the spin, is random. This kind of randomness presents a much lower barrier of entry to new or beginner players as each individual game places less of a focus on skill - the skill of handling games featuring output randomness comes instead from the strategies or systems employed in managing them over multiple sessions.


Input and output randomness are two distinctly different kinds of randomness that each inject their own flavour into casino games. Designing a casino game featuring one or the other (or indeed a combination of both!) yields very different experiences for prospective players. Input randomness will reward players looking for long-term commitment to learning and gaining skill at a particular game, whereas output randomness is a much less intense design philosophy that prioritises accessibility and thrill over maintained focus and dedication.

© 2020 Creativity Unleashed Limited - Privacy Statement | Contact Us