Never Lucky BabyRage: A Guide to RNG in Gaming

RNG is a term that gets thrown around a lot in the gaming community, usually with some degree of contempt. The negative connotation attached to the term, however, is likely due to a fundamental misunderstanding of randomness, what it adds to games, and how it can be managed by players.

The reality is, RNG is neither inherently good nor bad. When introduced appropriately, RNG  can make games more exciting, motivating, or even more skillful. In other situations, too wide a range of possible outcomes creates situations that are frustrating and reduce the impact of player decisions.

This article will cover the basics of randomness, its application to gaming, and some of the effects of has on perception and decision making.

Defining RNG

RNG stands for Random Number Generator. In computer programming there is frequently a need to select a number whose outcome cannot be foreseen [1] and a Random Number Generator fits the bill.

In the gaming community, however, the term “RNG” is frequently applied to situations in which the outcome cannot be predicted rather than the means of generating the randomness.


In classic Role-Playing Games, a 20-sided die (d20) is frequently used to determine outcomes. The results of the die-roll affect gameplay unpredictably: the die itself is the Random Number Generator and the outcomes associated with it may be loosely referred to as RNG.

Range of Outcomes

Within any Random Number Generator, there is a range of possible outcomes. Defining the Range of Outcomes contributes to better decision making.


When rolling the d20, the Range of Outcomes is outcomes is 1 through 20. As such, each there are 20 possible individual results.

Equality of Outcomes

A key component to randomness is that all outcomes have an equal probability of occurring. Remembering this is crucial to avoiding logical fallacies associated with random events.


Assuming a fair die, each possible outcome in the Range of the d20 is equally likely to occur. This means that a result of 1 is just as likely as a 20, or any other number on the die.

Success and Failure Outcomes

In gaming, success or failure is rarely reliant on a single value in the Range occurring. Instead, a subset of the possible values would be considered a positive outcome, or a Success and the rest of the Range can result in a negative outcome or Failure.


Before attempting to pick a character’s pocket, you must perform a skill check. Because your character has high Dexterity, you determine that you only need a roll of more than 4 for the check to pass. This means that the outcomes 5-20 would result in a Success, whereas 1-4 would be a Failure.

Likelihood of Success and Failure Outcomes

Splitting the Range of Outcomes into the binary distinction between Success and Failure allows for simpler calculations of probability. Instead of considering all possible values in the Range, only the two subsets must be weighed and quicker and better decision making.

  • The likelihood of a Success is the sum of all positive outcomes divided by the total number of outcomes in the Range.
  • The likelihood of a Failure is the sum of all negative outcomes divided by the total number of outcomes in the Range.


By segmenting the results of your Dexterity check into Success and Failure, you can determine that 16/20 (80%) of outcomes will be a Success and only 4/20 (20%) of results will be a Failure. You can easily determine that a Success is far more likely in this scenario, despite the randomness involved in die rolling.

Law of Averages

The Law of Averages [2] states that all possible outcomes will inevitably occur not matter how unlikely they may be. Frequently, the Law of Averages is applied irrationally and results in fallacious reasoning. Just because an outcome is possible, doesn’t make it reasonable to expect it to occur. Likewise, just because an outcome is highly likely, doesn’t make it reasonable to count on it.


Despite determining that a Success is very likely in your skill check, Failure is still a possibility. As a result, Failure is bound to happen in this scenario, at least occasionally.

Even more unlikely is the Failure happening several times in a row in identical situations. However, because Failure is always a possibility, bad streaks of negative outcomes will inevitably occur. This fact does not change the probability of a Failure happening 20% of the time.

Law of Large Numbers

The Law of Large Numbers (LLN) [3] relates to performing the same trial several times. With a large enough number of trials, the results will stabilize to the expected distribution. This means that:


As a result of the Law of Averages, you failed your Dex check five times in a row. However, given enough attempts at picking pockets, the outcomes will eventually normalize to the 80% Success rate that is expected in the situation.

This does not mean, however, that Success is any more likely after a series of Failures. Rather, it means that when evaluating your decision, you can say that more often than not you can anticipate a Success and it was a good choice.

RNG in Video Games

Random Number Generation (RNG) is included in a variety of video games, adding a layer of unpredictability and excitement to game play. Role-playing Games and Card Games, especially, have obvious elements of RNG incorporated in them.


As an offshoot of table-top Role-playing games used in the examples above, the RPG video game genre utilize RNG to determine outcomes in numerous situations. Damage calculations, combat events, and rewards all have a degree of uncertainty in their outcomes.

Damage Range

In RPGs, damage output is typically dynamic. Abilities and basic attacks alike usually have a Range of possible damage that is used rather than a static value. For instance, rather than a weapon constantly striking for the same amount of damage each swing (100), it may have a wide (25-175) or narrow (90-110) range of potential damage output.

Both of these sample weapons have the same mid-range and potential for the same damage over a long period time. The variations in range, however, requires players to make a decision about what would benefit their character most. Consistent damage output via the narrow range is beneficial to some, but characters with abilities reliant on burst may favor a wide range with more top end damage potential.

Combat Events

Similarly, combat events such as dodges, parries, and critical hits occur somewhat randomly. The unpredictable nature of these events makes them inconsistent but can offer the potential to turn the tide of battle.

Players can equip items and upgrade stats to make these combat events more likely, but, just like with the dice roll examples, periods of drought can occur. Likewise, several crits in a row are possible which can decimate enemies and make the player feel powerful.

Loot Drops

While guaranteed item drops may seem great for the player, this would disincentivize continued play. If you get the loot you were looking for on the first boss kill, why bother running through the dungeon another time?

As such, somewhat random rewards provide a carrot for players to continue running dropping bosses and playing the game. With regard to loot drops, RNG provides motivation for continued play.

Other games, such as First Person Shooters (FPS), that are devoid of RNG in game play borrow from this practice in their rewards system. In doing so, they offer a similar incentive for continued play.

RNG in Card Games

Randomness is an inherent component of all card games. Drawing the right cards in the right order is determined randomly. Likewise, digital card games now offer the capability of random events, adding a second layer of RNG in the game.

Draw Order

When it comes to the outcome of card games, the randomness that has the biggest impact is draw order. Drawing exclusively high-cost cards in the early turns means you have nothing to play in the early game. Likewise, top decking low mana cards in the late game leads to weak turns.

That said, each card in a deck has an equal chance of being drawn. As a result, depending on the structure of your deck, you may be just as likely (or more) to draw the perfect combination of cards in the right order as you are to draw dead.

Random Events

In addition to draw order, random events are frequently tied to card text. These events mimic the combat events found in RPGs to add variance to gameplay. Summoning random minions or dealing random damage is a common example of this. However, most of these random events have a narrow range and a more predictable than draw order.

RNG: The Good, The Bad, and The Ugly

In video games, RNG adds a bit of unpredictability in our gaming experience. Having unexpected outcomes can prevent games from getting stale or provide an incentive for continued play. At times, however, the unpredictability can be frustrating or give the feeling of the outcome being completely out of our hands as players. More damaging, however, is that a misunderstanding of RNG can lead to fallacious thinking that results in poor decisions and perpetuates bad results.

The Good: Excitement

The unpredictable nature of random events makes them exciting for players and spectators alike. Repetition in videos games quickly leads to staleness, reducing the desire for continued play and viewership. By injecting RNG into games, developers can create new experiences in familiar situations.

The anticipation of a range of possibilities affects both gameplay itself and rewards for playing. While many gamers may desire rewards be given to them freely, doing would quickly reduce one of the major incentives for continued play.

The Bad: Inconsistency

Varied outcomes can be a double-edged sword. The same unpredictability of RNG that creates excitement can quickly lead to inconsistency.

Problems arise with RNG when the Range of Outcomes is too wide. Some unpredictability is good, but when it wins and losses are completely determined by extreme outcomes, players quickly become frustrated by inconsistent results.

Imagine, for instance, that a weapon does poor damage overall but has a 5% chance on hit to kill enemies immediately. This might make the player feel powerful at first, but the lack of effort and reliability quickly becomes dissatisfying. Worse yet, in a competitive environment, opposing players who are slain by this random proc feel helpless against it, despite winning the majority of the time.

The Ugly: Biased Thinking

Problems frequently arise with RNG when we misunderstand the concept of randomness. Connecting future outcomes to previous random events is a common issue that creates false expectations for results.

Humans excel at pattern recognition. So much so, that we often incorrectly identify patterns where they do not exist. When it comes to RNG, this creates the potential for biased thinking. In particular, a fundamental misunderstanding of the Law of Averages leads us to believe outcomes are more/less likely than they actually are.

Gambler’s Fallacy

The Gambler’s Fallacy [4] is one such example in which we have a tendency to believe that future outcomes are more likely to occur based on past events. It’s true that the Law of Large Numbers tells us that, over time, outcomes will stabilize to the expected value. This does not, however, affect the probability of individual events. Each outcome in each trial retains its expected probability, regardless of what happened in previous tests.

Back to our d20 example, a player falling victim to the Gambler’s Fallacy would believe that, after five failed pickpocketing attempts, the next check is more likely to succeed. He or she would go into the roll assuming that Success is all but guaranteed to end well thanks to past failures. In reality, nothing has changed and Failure is still likely to happen 20% of the time.

Hot-hand Fallacy

Similarly, the Hot-hand Fallacy [5] ties future random events to past outcomes. In this case, players incorrectly believe that they are having a streak of good luck that improves their upcoming chances of success. This frequently leads to overconfidence and poor decisions.

For instance, a player who has had several successful pickpocket rolls in a row may feel he or she has a hot hand. Despite calculating poor odds, the player decides to attempt to pickpocket a character with high wisdom. Past outcomes, despite having no implications on the outcome of future events, caused the player to be overconfident and take an unnecessary risk.

You can see how both of these fallacies taken together reveal the human tendency to hope for and unreasonably expect positive outcomes for oneself. This tendency also forms the basis for misplaced feelings of betrayal or sense of unfairness when a negative outcome inevitably occurs.

RNG and Fairness

RNG is inherently fair. As defined earlier, randomness requires all outcomes to have an equal probability of occurring. Typically, frustrations are not a problem with the RNG itself, rather, flawed memories or unreasonable expectations of results.

Favoring Negative Outcomes

The events that tend to be more memorable play into our false assumptions about RNG as well. In general, humans tend to fixate negative events [6]. As a result, when remembering random events we are more likely to recall negative outcomes than positive results.

In doing so, however, we run the risk of making false assumptions about the probability of specific events, such as overestimating the likelihood of negative outcomes.

Event Salience

The salience, or degree to which something stands out, of an outcome, also impacts our memory of it. Events that are less common tend to be more salient than those that are common place.

In card games, the availability of cards to play (from random draw order) directly results in wins and losses more often than a random event in turns. However, we cling to less common (but more extreme outcomes) that sway the game in these random events.

A Madder Bomber hitting exclusively your own face when an opponent has a full board of weak minions is certainly frustrating and memorable. However, the game was likely dictated by the random, negative draw sequence you had in the turns prior, not your unfortunate RNG. Even still, if you’re like most, you’ll have a tendency to remember the Bomber turn and blame the loss on that outcome.


Flawed memories cause us to incorrectly assume we are naturally unlucky when it comes to games of chance. Our perception of past events is clouded by a combination of our fixation on negative outcomes and the salience of outlier events.

Returning to our d20, failing miserably with a roll of 1 is just as likely as a roll of 13, but we fixate more on the former because of the extreme nature of the roll (and the outcomes associated with it). Coupled with our fixation on negative events, the outlier, Failure roll (1) is more likely to be remembered than the common, Success roll (13) that occurred earlier. Often, these results lead to the player’s resignation that they’re “never lucky”.

In reality, clusters of good and/or bad events can happen to anyone equally. This is the result of randomness expected due to the Law of Averages. It has nothing to do with the person being born lucky/unlucky [7]. Rather, it is an expected consequence of a random world.

RNG and Skill

Frequently, players consider games that contain randomness to therefore exclude skill. The idea here is the belief that the randomness is so powerful a dictator of the outcome, that the player’s choice has no or little impact. In this perspective, the game is reduced to luck or chance with no room for intelligent or skillful play. To the contrary, it’s possible for a game to be devoid of RNG and still require no skill, just as much as it is possible for RNG and skill both to be present in a game, as shown in the graphic below.

RNG and Skill can be plotted on a four quadrant scale.

While random outcomes are outside of the player’s hand, the decisions made prior to and as a result of these events are directly under the player’s control.

More simply, how we weigh the possibilities of randomness and to what degree we are influenced by random events is a skill. Granted, this may not be the same type of skill required to snipe a player across the map with low visibility or position your hero optimally on the map, but it is a skill nonetheless.

Individual Outcomes vs. Game State

Properly managing RNG requires more than simply weighing the probability of individual outcomes. Players must also consider the current state of the game and how much the potential outcomes will influence the result. As such, when making a decision about potential plays, gamers must consider both the Risk and the Reward of the outcome. In these situations, Risk is the probability of Success while Reward is the degree to which a Success impacts the game state.

Playing Not to Lose

When behind in a game, a high-probability play, while safer and more likely to result in a Success, accomplishes little in terms of catching up to an opponent. Frequently, these low-risk, low-reward player are referred to as “playing not to lose” because they might offer survival, but don’t provide the opportunity to swing the game state back into the player’s favor. Instead a high-risk, high-reward play may provide a better chance of winning the game, despite the individual play having a lower probability of success.

Avoiding Unnecessary Risks

Inversely, when ahead in the game it’s often best to avoid high-risk plays even if the reward is great. In these situations, players need to favor plays with few highly-unfavorable outcomes and focus on low-risk plays that maintain their lead. Gamers skilled in RNG management can recognize these circumstances like these and act accordingly.

Tips for Managing RNG in Game

Like other skills, learning to manage RNG in games requires experience. This article has provided the context for RNG in gaming as well as mindsets to avoid when confronted with choices that involve random outcomes. The tips below summarize these topics into a few critical points for managing RNG in game.

  • Identify the full range of possible outcomes.
  • Determine which outcomes would be a Success and which would result in Failure.
  • Weigh the impact of a Success against the downside of a Failure (i.e., determine which has a greater impact on the game state).
  • Make a decision based on the probability of Success/Failure and the impact on the game state.
  • Do NOT consider past results when weighing RNG outcomes.
  • Do NOT let your beliefs of having generally good/bad luck influence your choices.

Game better.

How do you manage the RNG in the games you play? Share your tips and experiences in the comment section below!

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