[miguel_marinheiro]

There are plenty of articles and videos on RNG (stands for Random Number Generators) out there so I thought I’d throw in my own perspective as well, this comes from my reading on the topic and also personal experience from playing games with big luck elements.

Let’s start with an important question, what makes a game.. a game?

There are certainly many definitions out there, although I’d argue that uncertainty in outcome is one of the main ingredients of a game.

Seriously think about it, from card games in which you can have an almost unlimited permutation of cards (52 factorial), to dice used in many board games, to sports where the uncertainty factor comes from human beings themselves and environmental factors like wind.

However it’s important to distinguish randomness or luck from random elements, random elements can be cards or dice. These random elements can increase the amount of randomness.

Rock-Paper-Scissor for example has no obvious random elements but it is highly uncertain.

Before I became a game designer I was a fairly competitive player. One of the things that usually comes from being an “hardcore” player of any game is that you see luck as a bad thing since it means your skill matters less, and hardcore players really like to express their skill.

However if we took that idea at face value, what would that mean for the game of poker, poker has tournaments and overall the perception is that it’s a highly skilled game but it also has a big luck component, you can get bad hands.

Another game we can look at is Chess (another favorite of mine). Chess is a game with a lot of skill (like poker) but very little luck. In fact you could make a table like this.

	Almost no luck	Lots of Luck
Lots of Skill	Chess	Poker
Almost no skill	Tic-Tac-Toe	Candyland

When you play chess though, you don’t think of it as a “solved” game with no uncertainty even though it has no obvious luck based elements. It becomes “random” because of the complexity of the game.

If any human had the capacity to fully solve chess it would in fact stop becoming “random” and it would be more of an algorithm, pretty much like anyone that has played Tic-Tac-Toe more than 10 times can ensure a draw (Tic-Tac-Toe has a very small problem space so it’s easily solvable).

I’ll bring the example of Company of heroes, if you haven’t played the game don’t worry, the same concepts could be applied to your games as well.

RNG in Company Of Heroes:

I’ll start by briefly explaining what Company of Heroes is since I’m sure many readers wouldn’t have either heard of or played the game.

Company of Heroes is a World War 2 Real-Time Strategy simulation game, it has heavy inspirations from Band of Brothers and Saving Private Ryan. You are an army commander that can control squads of infantry and tanks, because the game wanted to simulate a war experience, many systems use RNG.

This includes:

• Squad Behaviors: Certain soldiers would at random intervals seek cover while in combat, soldiers would “lag” behind the rest of the squad and then catch up randomly, among other similar behaviors.
• Artillery: Artillery bombardments would also be random within a certain radius.
• Shots: Units have accuracy values, meaning they don’t always hit their target even when in close proximity.

What I want to highlight is how Company of Heroes used luck to its advantage.

Fog of War:

This one is not inherent to just Company of Heroes, in fact most RTS games have it,  but I’ll still highlight it, fog of war in games is a way to have hidden information. This introduces a source of randomness, often called von Neumann games, in which players are making simultaneous choices and then resolving the outcome. This is no different than Rock-Paper-Scissors.

This introduces a layer of uncertainty to the game, for Company of Heroes this helps fortify the notion that “you never know when you’re going to be met with heavy machine gun fire”. It creates tension.

Luck as a way to create emergent moments:

The game implements various RNG based systems, one of them is called “Vehicle Criticals”, in practice this meant that your tanks could get debuffs applied to them which were chosen randomly, some examples are:

• Gunner killed: If your vehicle had someone on the pintle mount machine gun they could get killed, not through any link to the actual health bar of the vehicle but randomly.
• Main gun destroyed: Your vehicles could get their main gun destroyed, rendering them “useless” until repaired.
• Engine Critical: Your vehicles could get their engine damaged or destroyed which affected the mobility of the vehicle.
• Death Criticals: Your vehicles would be “Out Of Control” and ram into something, in Company of Heroes 2, this was brought ever further with a “Abandoned” Critical that allowed your opponent to snatch the vehicles for themselves.

This effectively made the narrative of each match a lot more compelling, you never knew what could happen in a game, this supported the game’s design vision of “Each battle tells a story”.

You could be driving a tank through a road, hit a mine and now your tank threads would break, this dynamically created a moment in the game where you need to support your valuable tank by defending its position and repairing it. For Company of Heroes this RNG system enhanced the narrative experience.

The game also had RNG on infantry combat, not only on the weapon accuracy mentioned above but in Company of Heroes 1 infantry squads could roll a critical hit which would straight up kill a soldier, opposed to just reducing its health. This once more made each combat encounter feel more alive and real.

Another interesting factor is that usually scenarios of really good luck or really bad luck create memorable scenarios.

Luck as a way to catch-up:

Usually in video-games it’s important that all/most participants feel like they still have a shot at winning, if you played some classical board games like Monopoly you would know about the slow death spiral the game provides. You could be playing a game where the game was lost about 1 hour ago, this makes the game really unfun.

One example on the opposite side of the spectrum is Mario Kart, this game has random power-ups, one of them called the “Bullet Bill”, and it creates a moment in the game where the last player can be put directly at the front of the pack again.

Company of heroes also has an element of this, if we look at the criticals above it has yet another useful purpose, the player that is ahead can get affected by really bad random elements putting the player less further ahead. It could happen that your really awesome tank gets its main gun blown off and it becomes not so awesome anymore.

This concept at first might be counter-intuitive but luck is a catch-up mechanic, often the player that is ahead is the one that wants to avoid RNG to maintain their lead, the player that is behind is the one that benefits from RNG happening in the game since it can propel them back up. If you’re behind in the match and bad RNG happens it doesn’t really matter since the game was already heading to a loss scenario regardless, however if you’re ahead in a match and bad RNG happens then it does matter.

Although there also needs to be a balance, in Company of Heroes 2 the vehicle abandon mechanic got a very bad reputation and was generally disliked by players, that vehicle critical meant that not only were you losing a powerful vehicle but your opponent was getting it. You need to be careful to make the RNG factor not be big enough that it feels that your advantage is meaningless. This can be observed often in board games oriented to younger audiences where luck is usually the main factor of the game, giving everyone always a chance at winning.

Increased range of competition:

If you want your game to succeed you need players, to have players your game needs to be somewhat accessible, the more accessible it is the more players you have. If you’re playing chess and you get someone 100 Elo points rated higher than you there’s a big chance you’re going to lose, so you feel demotivated, that feeling is not good for player retention.

RNG can help the game become more accessible . Luck introduces a higher chance you could upset your opponent, giving you more overall fun engaging with the game. The less luck your game has the harder it will be for you as a player to have played a match where you felt like it was balanced.

Luck as an ego crutch:

This one is often overlooked but is also an important factor, I myself have used it while playing Company Of Heroes a lot. No one likes having their ego affected, especially competitive players.

It’s a natural human tendency to take credit for our wins and blame the fates (or luck) for our losses. The more random elements a game has the easier it is to do that.

This also provides a layer for casual players to experiment with new play styles or strategies.

Player Acceptance of RNG:

In general since the benefits of RNG are unclear, players are usually not accepting of it. You can double or triple this assumption for highly enfranchised players (such is the case with Company of Heroes), there is a certain trend among games with various installments to remove RNG factors along the way.

Company of heroes specifically has removed various RNG factors along the history of the franchise. Speaking from direct experience for the longest time as a top player for the game I disliked the RNG factors without realizing that those same factors were the ones that made me fall in love with the game in the first place. This happens in many games, usually hardcore players advocate for the removal of RNG essentially shutting the door behind them for newer players that would have liked to engage with them.

This is a challenge for game designers, you want to create a new game for your franchise but you have a challenge that you didn’t have originally, you already built a fan base, part of which is an hardcore fan base.

These players have mastered the game, as such they want less RNG elements so that they can demonstrate their skill better.

This puts game designers in a tough spot where they need to balance existing player expectations with new players who you might want to acquire that are less likely to even try the game.

One interesting historical fact is that chess used to have actual sources of randomness, in the 11th and 14th century dice were thrown before each turn to determine the piece to be moved.

Before ending this post, I’ll bring an interesting example of an established franchise that was able to re-add RNG to great effect. Team Fortress 2 is that game, the game designers at Valve had the objective to broaden the appeal of the game beyond a niche audience, as such they introduced “wild criticals” to the game. After a couple of weeks they had much more positive reviews and playtesters “couldn’t put their finger on why the game seemed so much more fun”.

However once hardcore players fully understood the system it was put under scrutiny again.