Horizon Forbidden West sees Aloy traversing dangerous and harsh environments in search of the underfunctions of Gaia, in hopes of restoring the planet’s terraforming system, rebalancing the biosphere, and saving life on Earth. Although our story is set 1,000 years in the future, players will discover and recognize many iconic locations in our real world today.
DISCLAIMER: Please note that this behind the scenes feature contains major storyline spoilers and many gameplay elements of Horizon Forbidden West. To get the most out of this in-depth article, we strongly recommend that you complete The Sea of Sand quest before reading it.
During The Sea of Sands quest, Aloy ventures into the arid wasteland of Stillsands in search of Poseidon, one of Gaia’s sub-functions. At first the desert seems desolate, however, hidden beneath the sand are the flooded ruins known as Dunehollow, formerly Las Vegas.
It’s up to Aloy to piece together the data fragments left behind a millennium earlier by a businessman named Stanley Chen and reactivate the city’s long-forgotten water systems in order to access Poseidon.
Create the Vegas Ruins
Guerrilla Quest designer Samantha Schoonen led the development of this quest, The Sea of Sands, from start to finish. To bring this vision to life, she did extensive research on the iconic Vegas Strip.
“We looked at casinos and came up with crazy ideas for distant Vegas buildings,” says Schoonen. “I also drew a lot of inspiration from our concept art, and we thought of things like a broken down roller coaster area, the remains of a pirate ship and a rooftop swimming pool – we worked a lot with our art departments to figure out what would work, although of course not everything was included in the final game.
Designing this epic questline was a long process full of iteration and collaboration, says Samantha. “For main quests, we always start with a story summary provided by our Narrative team,” she says. “Based on this summary, we write a design document containing all the information, such as story beats, quest objectives, a world map of the area to give an overview of the flow and locations of the quest, and a detailed description of these areas.
“We then make an outline of the space. I use in-game reference images to get an idea of the level design and the space itself, the outlines. But it’s hard to get a scale of the place working only in 2D, so as soon as possible I create a 3D layout in our Decima Engine. We then continue to iterate on the flow and level design until everyone is happy.
An underground challenge
“Building a quest that uses water has always been a challenge,” says Schoonen. “I remember how difficult it was to build the Waterlogged quest for Horizon Zero Dawn: Frozen Wilds, and of course Las Vegas would be much bigger! We worked closely with various teams such as technology, effects visuals and lighting to make sure we had the systems in place for the underwater quests to work, we wanted to control where the water would be, as well as the air pockets, and the visibility needed to be adjustable.
“We also worked closely with core design, which was in charge of the swimming mechanics. This would be the first quest where the player could dive to previously unreachable depths.
Core systems designer Lennart Hoting worked on a number of aspects of traversal, including swimming and diving, which are new to Horizon Forbidden West. “We were looking for new heights and new depths to explore and new kinds of natural beauty to showcase,” says Hoting. “As the underwater world is inherently fascinating and mysterious, it felt like a natural extension to traversing long-lost unknown places like Las Vegas. focused on fast and agile traversal, with enemy encounters revolving around stealth to add tension.
“Early in development, we investigated which aspects of water could provide interesting gameplay challenges while increasing immersion. Water currents quickly came to mind. water that will take her away from where she wants to go. You can try sprinting through them, but the best way to get past them is to use underwater boost bars. Aloy can grab them and push them away to gain a short boost that can propel her straight through.
Create tension in tight spaces
As Aloy acquires the scuba mask, giving her unlimited airflow underwater, she dives into the ruins of Vegas. “Our initial traversal routes were far too long, so we decided to have a single elevator shaft going up or down,” Schoonen explains. “This shaft couldn’t be too big due to the above ground visuals, nor too small for the player to move through or the elevator to operate after the quest was completed.
“Once Aloy swims through the elevator shaft, she enters a Casino space and eventually the lobby. I really wanted the player to be immediately caught off guard by the Tideripper before becoming aware of the size of the gap as a large opening.
There are some rather dangerous machines in the waters of the F orbidden West, including Burrowers, Snapmaws, and huge Tiderippers. “Aloy has no way to attack while swimming, so she has to be smart and stealthy to get around enemies,” Hoting adds. “The best way to stay out of sight is to use smoke bombs or hide in kelp. These plants grow dense enough to prevent oblivious machines from spotting you while still giving you the ability to peek while hiding inside. This creates a moment of extremely tactical cat-and-mouse gameplay.
Samantha continues on this underground location. “The underground dome is a dangerous place full of machinery, so we’ve added a few structures for the player to hide in as they move between hideouts,” she says. “Machines are on patrol paths, which change each time a node is activated. We then place the machines along the player’s route to their next location to create an ever-present threat.
“Many areas went through various iterations, as building entrances, nodes, and sewers had to be out of sight but not impossible to locate. The real world of Las Vegas draws its water from the Nevada Hoover Dam, so we wanted to convey something similar with the holographic map the player encounters at the start of the quest.
“We were so inspired by Vegas and wanted to make the quest worth it. By integrating multiple elements, such as tracking, combat, stealth, and small traversal puzzles, the player enjoys a variety of gameplay to keep him feeling fresh. It was really hard to add enough elements without relying on combat and puzzles, which are mostly physics-based. That’s why we also added air pockets where the player could walk through and interact with the environment.
The Tideripper Trial
After Aloy successfully crosses the infested waters of Snapmaw and activates Stanley Chen’s old water management system, water flows out of the town. Suddenly, the scale of the dome and the buildings within becomes clear. Aloy must navigate them in a more traditional way by climbing, sliding and running, with the dome becoming a large arena for an impressive battle.
Do you remember that Tideripper mentioned earlier? With most of the water now drained from Dunehollow, Aloy will still have to deal with this difficult machine before finally arriving at Poseidon.
Samantha Schoonen explains how the arena for this battle was created. “We worked with the combat team because this space required several elements to function,” she says. “The Tideripper needed a body of water to emerge from, so we built a kind of beach where it could fill its Purgewater Sacs. The arena also had to be deep enough that the player wouldn’t accidentally leave the area. Finally, it needed a flat space for the Tideripper to move around in and, of course, grappling hook points for Aloy to get away quickly – although some of these needed to be destructible for an added challenge!”
A beautiful view
After defeating the Tideripper and obtaining Poseidon, Las Vegas truly comes to life. Fascinating holograms light up the sky with the ghostly outlines of buildings that crumbled long ago; memories of a forgotten city.
“Making Vegas bloom visually has always been part of the narrative vision for this quest,” Schoonen says with a smile. “Poseidon has taken over Vegas’ power and water supply that was connected to the holograms. After Aloy battles the AI, the system fully reboots and the original holograms take their place to light up the night sky. The end of the quest was a huge collaboration; teams like concept art, cutscenes, environment art, visual effects and lighting all worked together on this beautiful moment. I just put them in the right places and I made sure they showed up at the right time.
“We all put a lot of love into building this area. I’m amazed at how well received this quest has been and I’m happy to hear that the community had a great time playing in this underwater world!”
When it comes to her favorite moment, Samantha Schoonen has a hard time choosing. “For a designer, a game is never finished,” she says. “I would have to look back ten years to have a clear opinion because I played there so many times during development. I think it’s more the whole build journey of this quest; it’s my favorite part.
And as for Lennart, he says, “I really liked seeing that many players enjoyed the underwater sections of the game and some even said it was their favorite part. The Sea of Sands quest response and love for unique characters like Morlund you meet along the way has been particularly great; it’s one of my favorite quests. While some players remained anxious about diving, the diving mask really seemed to turn these sections into something players enjoy. To read that people were able to overcome their fears and enjoy the diving experience is amazing.
There’s a lot more to discover in and around Vegas after the Sea of Sand quest, which now includes a settlement called Hidden Ember; we certainly encourage you to come back for a special quest with Morlund, talk to Porguf at Camp Nowhere or deliver ornaments to Stemmur and wonder about the Ancients’ vacation as they light up the skies of Vegas. If you’re interested in addition to the story behind the Vegas ruins, you can rewatch our recent livestream with Samantha here (we are live every Thursday at 4pm CEST, www.twitch.tv/guerrilla).