Jan 18, 2021 7:00 AM

Why Do Exploding Barrels Make Video Games So Much More Fun?

Elemental reactions, like shooting a dynamite-filled barrel or using an ice spell to cross a stream, are an important way for designers to bring worlds to life.

Too often game worlds can feel like static backdrops for gameplay. But by incorporating elemental reactions, developers bring complexity and characterization to a player’s surroundings.

By now we’re all familiar with the overused exploding barrel trope. A single bullet is all it takes to create an explosion that can take out multiple enemies, turning an element in the environment into an interactive arrow in your quiver as you progress. While environmental storytelling has stolen the spotlight when it comes to designing spaces, emergent environmental narrative design is quietly the bigger innovation happening in games right now, with elemental reactions being the easiest to grasp.

If games are big iterations of cause and effect, then elemental reactions give very clear and logical feedback to players about exactly what their footprint on the world is. What’s more, modern games that embrace elemental reactions, like Divinity: Original Sin, Genshin Impact, and Noita, also give their worlds and characters more personality and texture, creating a space that’s much more alive and free-flowing than you normally see in game worlds.

What Are Elemental Reactions in Games?

The exploding barrel example works like this: You wait until enemies are in proximity of the barrel, then you ignite it somehow, causing it to combust and send them flying. Cause and effect here are clear, and the game world becomes part of your strategy. Suddenly the environment becomes more of a third party that you can use and interact with. In the old days of games like DOOM (1993), this meant keeping an eye out for more exploding barrels, but games eventually got better at environmental interaction by looking to other elements.

One classic example is water puddles used in tandem with electricity powers in BioShock (2007). Just like the exploding barrel trick, you have to wait until enemies are in position, but here the impact area is marked by the wet floor, so you can clearly see who and what will be affected. More importantly, though, is the fact that this interaction is immediately apparent without much explanation to the player. Of course zapping a water puddle will electrify anyone standing in it. Basic elemental reactions are effects that everyone can intuit.

At the same time, elemental strengths and weaknesses, both explicit and implicit, have been part of role-playing games and card games since the beginning, with roots stretching all the way back to tabletop RPG Dungeons & Dragons (1974) and reaching an apotheosis with Pokémon, in both video game and trading card game form. The backbone of both Pokémon games is a complex chart of type strengths and weaknesses, making for a convoluted game of rock, paper, scissors. It’s why elemental diversity is generally encouraged in most competitive Pokémon teams, and though card decks can’t be diverse by design, they can work to mitigate any disadvantages they come across. Every Pokémon type becomes something of a character in and of itself.

How Developers Use Elemental Reactions to Improve Gameplay

Of course, Pokémon generally doesn’t deal with interesting combination effects very often, merely doing more or less damage. Recent smash hit Genshin Impact takes this a step further and weaves elemental reactions into both combat and exploration. You play as a party of characters that you can swap among on the fly, each of which has an elemental quality to their powers. Combining certain elements will create new effects that can make your strikes more powerful, impede the enemy, or even get you more resources. Combining ice and electricity, for example, makes the “superconduct” effect, which deals ice damage in an area and reduces physical resistance. And the fact that you can switch between characters on the fly means that you can smoothly create some big effects, depending on what you’re facing, in the blink of an eye.

But the elemental shenanigans don’t stop at the battles, as your elemental affinities help you in your exploration too. Whether you’re freezing a body of water to walk across or burning a piece of debris out of your way, using your elements wisely is a vital part of the Genshin Impact experience and is sewn into the very fabric of the gameplay.

Many designers are taking the same principles used in making Pokémon’s types into characters and bringing them to environmental effects in some dynamic ways. Take Divinity: Original Sin 2. Every battle in the game takes place on a small plot of land, much like the old Baldur’s Gate games. The difference here is the potential for environmental interaction, which takes the form of features in the setting and magic spells. A nod to the old exploding barrel, you’ll often find barrels full of substances that are ready to be poked with a spell or effect—most often oil, which will either spill all over if you destroy it or explode if you ignite it. Most of the environmental effects will be caused by you, though, with the battlefield serving as a canvas for your elemental spells. A rain spell will douse the land in water, putting out fires and making puddles. From there, you can use an electric spell to stun enemies, though you’re not exempt from taking a shock if you’re wet too. Soon the battlefield changes and becomes characterized by the magical scars of battle, textured with strategic choices both past and future.

2011’s Magicka deserves special mention here as instructive of how elemental combinations work in concert with each other simply by virtue of being built around multiplayer. There are eight different elements that are associated with the different spells you can cast in the game, which each have their own properties that mix with each other. But you don’t have to figure it out on your own. Other players are also experimenting with spells, which will inevitably have you crossing the streams and discovering these combinations just through normal play. Players can then incorporate these interactions into their future strategies and preferences, giving texture to the journey as a whole.

The design philosophy behind the Divinity: Original Sin games takes this a step further by making these reactions a resource to compete over. “Environmental interactivity adds a new dimension to combat that the player and the AI can compete over,” says Nick Pechenin, lead systems designer at Divinity developer Larian. “Together with stealth and summoning, manipulating the environment presents a situational alternative to head-on fighting, and we strive to make it equally viable in most encounters.”

Courtesy of Nolla Games

Elemental reactions can also give procedurally generated levels a more lived-in character. The roguelite Noita uses this to great effect in concert with the mind-boggling number of magic wand ability combinations you can use. Every game seed features elements like gunpowder, oil, and water dotting the cavern, which react to your abilities in extremely chaotic yet expected ways, making every run memorable and resisting the tendency of many procedurally generated level designs to be samey. These elements give a certain texture to every run, complicating them in different ways and giving every playthrough a chance to descend into accelerating chaos.

Balancing these chain reactions reveals how similarly designers treat the players’ abilities and the reactions themselves. “The effects of interactable pieces are generally defined in the same terms as the effects of spells and actions that the player or NPCs can perform,” Pechenin tells us. “So under the hood an oil barrel explosion is triggering a spell explosion similar to a small fireball. This lets us directly compare the payoff of engaging with such elements versus employing actions that players and their enemies have access to intrinsically.”

Characters aren’t the only things that can characterize the player’s experience in a game. We already ascribe traits to many non-sentient phenomenon found in nature, with the elements being the most instantly recognizable. The rain is something most of us have lived with all our lives, and we know its properties intimately just by experiencing it. They’re inscribed on our very sense of logic. As Pechenin explains, “The hidden strength of using the elements in systemic design is taking advantage of natural knowledge that players already have. We don’t need an elaborate tutorial to explain the idea that ‘fire burns flammable objects and touching it will hurt,’ as we can reasonably expect most players to know that already.”

By incorporating these elements in logical ways, developers can build more believable game worlds that we can connect with sooner and understand faster. Most of all, though, they make these worlds feel alive and dynamic, like an old friend you grew up with.