Section
World and levels
The idea
How a world is built: from large to smallLesson · beginnerWhy a world is built in passes over the whole map and not one corner at a time: concept, ground and water, roads and places, ground cover, details, light. What depends on what, why world tools are built so that everything can be redone, and where to start.World scale: meters, minutes and densityLesson · beginnerWhy the size of a world is counted in minutes of travel, not kilometers: the player’s height and speed, on foot and by car, draw distance, how much interesting stuff turns up along the way, and why a small dense world feels bigger than a big empty one.Open-world design: regions and landmarksLesson · coreHow an open world pulls the player forward without arrows: regions with a character of their own, landmarks seen from far away, hills that hide and reveal, emptiness as a pause. How it is done in Zelda, Firewatch and Ghost of Tsushima.A world you believe in: where people live and where the roads goLesson · coreWhy a village stands by water but above the floodplain, why a city grows at a ford, and why fields lie by the houses and forest on the slope. The site and situation of settlements, nodal points, the von Thünen rings that terrain bends, and the stories a place tells by itself.
Level design
Wayfinding: how players find the wayLesson · beginnerHow a player understands where to go: cues from quiet to direct, shapes that promise an action or forbid it, light, openings and movement, tracks and breadcrumbs, the yellow paint debate and checking a path with a playtest.Metrics: a level built around the hero’s bodyLesson · beginnerWhy a level is built from the hero’s numbers: player metrics and building metrics, a test map of boxes to measure the hero, jump height and distance with a safety margin, sizes of hallways, doors and stairs, cover heights and safe drops, and why metrics are not magic.Blockout: a world of boxesLesson · beginnerWhy a level is first built from plain shapes: what a blockout is, why it stays plain, five ways to build one, the loop of building, walking and changing, what is checked in it and when it stops helping.Layout: loops, forks and dead endsLesson · coreHow a level is shaped from above: the main path and side paths, loops and shortcuts that bring the player back to a familiar place, forks with a readable choice, dead ends that pay for the walk back, common patterns, and how to draw a plan on paper before building.Pacing: tension and restLesson · coreWhy a fight needs a quiet room after it: beats and set pieces, teach, test and twist, intensity graphs, rules of thumb and when to break them, the director of Left 4 Dead that brings threats in waves, and pacing in multiplayer maps and open worlds.Gates and keys: a world that opens piece by pieceLesson · coreHow a game keeps the player where they should be: hard and soft gates, locks and keys of every kind, abilities as keys, places seen before they can be reached, mission graphs that show how much choice a level gives, shortcuts and one-way doors, and why good gates don’t feel like walls.Verticality: height as a toolLesson · coreWhat height and depth give a level: a view from above and a threat from below, a way ahead seen from afar, floors, one-way drops, stairs and jump pads, what height does to cover, when height gets in the way, and why players rarely look up.
Space and combat
Composition in 3DLesson · coreHow the rules of composition work when the player holds the camera.Interior and exteriorLesson · coreHow a room differs from the street: scale indoors, the move from outside to inside, light and exposure, windows and doors, the story a room tells. How to keep interiors in a big world: as ready-made blocks, separate levels or layers.Encounters: arenas, cover and lines of fireLesson · coreHow a place makes a fight interesting: the fight as a short story, why players fight from doorways and how footholds, hidden information and one-way entrances draw them in, cover and sightlines, the mix of enemies and room to step back.Stealth levels: light, shadow, patrols and coverLesson · coreHow levels for hiding are built: a safe outside and a risky inside, light and shadow, floors that are quiet or loud, patrol routes with windows to slip through, cover as a tool rather than armor, and why the player must always understand whether they have been seen.Multiplayer maps: balance, lanes and chokepointsLesson · coreHow maps for players against players are kept fair: what balance and fairness mean, how to judge each area by its use, cost and information, lanes and rotations, chokepoints, why travel time from each start decides where teams meet, symmetry and its limits, and bold tuning through playtests.Level scripting: triggers, doors and scenesLesson · coreHow a level reacts to the player: what level designers script, how triggers work, why doors are famously hard, how short scenes are kept from falling apart, and how to make a script survive a player who comes the wrong way.
Terrain
Landscape: terrain from a heightmapLesson · beginnerHow the ground in games is built inside: a grid of vertices and a heightmap, meters per vertex and centimeters per height level, pieces of the grid and detail in the distance, brushes and edit layers. How Unreal, Unity and Godot do it, and what a heightmap cannot do.What real land looks likeLesson · coreWhy mountains, valleys and shores look the way they do: erosion, scree, deposits, river valleys and terraces. How terrain generators imitate the work of water and time, and why land without erosion looks like clay.Gaea: first stepsFlowStep by step: set the size in meters, build a mountain and hills from nodes, erode them, check heights and slopes, and export a 16-bit heightmap that Unreal can import with meters intact.Erosion in Gaea: water, talus and depositsLesson · coreWhat the erosion nodes actually compute: water carries rock away and drops it lower down, slopes slide back to a stable angle, soft and hard rock wear at different speeds, and all of it depends on the size of the world in meters. Why several passes of different strength look more natural than one.Terrain from a generator into the engineFlowStep by step: terrain from a generator or from real elevation data, a 16-bit heightmap, a size the engine accepts, the scale for height, the import into Unreal, and a check that meters stayed meters.Ground material: layers, slope and tilingLesson · coreHow the ground is painted with several layers: layer weights, blending by height, an automatic material by slope and height, hiding the repeat near and far, the seam between rock and soil, and grass that grows from a layer. With Unreal as the main example, and Unity and Godot alongside.Masks from terrain in Gaea: slope, flow and depositsLesson · coreHow the terrain itself tells where grass, rock and sand belong: maps of slope, height, water flow and deposits, how they are computed, combined and exported, and how they become ground layers and placement rules in the engine.Caves, arches and overhangs: when a heightmap isn’t enoughLesson · coreWhy a heightmap can’t make caves and overhangs and how games add them: rock meshes on top of the ground, holes in the landscape, voxel terrain and terrain made as a mesh. How to hide the seam and what each way costs.
Water and roads
Water in the world: lakes, rivers and shoresLesson · coreHow water works in a game: the level and the bed, why a river flows only downhill, the shore, depth and color, clarity, foam at the edge, the bottom. How water cuts its own place into the ground in Unreal and how other engines make it.Lake and river in UnrealFlowStep by step: a lake and a river with the Water system. The bed in the landscape, the level, the shoreline, the flow, the material and a check from the player’s camera.Roads and trailsLesson · coreHow a road lies on the terrain: grade, turns and switchbacks, bridges and fords, shoulders and ruts, a trail that people wore in. What roads are made of: a spline that presses the ground down, a mesh along a spline, decals, in Unreal and other engines.
Vegetation and placement
Biomes: how a forest is builtLesson · beginnerWhy nothing in nature grows evenly: forest layers, moisture, slope, height and light, edges and clearings, groups and loners, old and young trees. The rules of nature that later become placement rules.Scattering by rulesLesson · coreHow a computer plants hectares: points on a surface, density maps, filters by slope and height, scatter without overlaps, the seed of randomness, recomputing after edits, generation around the player. PCG in Unreal and how other tools do the same; what rules cannot do and where an artist’s hand is needed.Plant a forest by rules in PCGFlowStep by step in Unreal: build a PCG graph that goes from bare surface to finished forest, with points, filters by slope and height, layers, clearings, exclusions for water and the road, and manual edits on top.Placing things along roads and shoresFlowStep by step in Unreal: PCG along a spline. Reeds by the water, rocks on the shoulder and fence posts along a path.
Large worlds
Air and distance: fog, sky and time of dayLesson · coreWhy the distance is lighter and bluer and how aerial perspective sells scale; fog, sky and sun as one system, time of day and weather, and how air guides the eye.Open world: how it loads in piecesLesson · in depthHow a big world loads around the player: a grid of cells, loading range, simplified copies in the distance, world layers, large coordinates and what breaks at the seams between pieces. World Partition in Unreal and how other engines solve it.Open-world budgetCheat sheetOne screen of numbers and checks: landscape sizes, cells and loading ranges, vegetation density, draw distance, what to look at in the profiler, and a checklist before you expand the world.
World breakdowns
Zelda: Breath of the Wild — triangles and gravityBreakdownHow Nintendo leads players across a huge field without markers: places that pull each player by what they want, land shaped as triangles that hide and reveal, the road to a tower in five steps, checking on foot, and three rulers for sizing the world.Firewatch: a forest built by a small teamBreakdownHow a team of about a dozen people built a stylized forest that leads the player without a map on the screen: a poster turned into 3D with fog from a ramp of colors, color from light rather than textures, a few trees placed thousands of times, space carved from the land, a paper map in the hero’s hands.Horizon Zero Dawn: placing a world by rulesBreakdownHow Guerrilla placed all the nature of Horizon Zero Dawn by rules, on the graphics card, around the player: the land as a stack of maps, graphs of rules that give each plant a density, a dither pattern that turns density into exact spots, and kinds of trees that share one pattern so they never collide.Far Cry 5: a world built by rules in HoudiniBreakdownHow Ubisoft rebuilt the cliffs, rivers, fences, power lines and forests of Far Cry 5 from the terrain every night with tools made in Houdini: the goals, the pipeline inside the editor, cliffs from the slope, and species that compete for the ground, while artists kept reshaping the land.Ghost of Tsushima: the island, the grass and the windBreakdownHow Sucker Punch fit the island of Tsushima onto a PS4 with napkin math and maps instead of objects, built the land in the engine, grew fields of grass on the GPU, drove everything from one wind, and turned that wind into the way the game leads the player.Epic’s PCG samples: assemblies, flat ground and biomesBreakdownWhat to learn from Epic’s free PCG examples that open in Unreal Engine: hand-built assemblies turned into points and varied by rules, point hierarchies, the Flat Area Detector that keeps flat assets off bumps, and the Biome Core plugin, a biome tool made of graphs.
Level breakdowns
How to study someone else’s levelFlowStep by step: play the level once as a player, draw it from above, mark the critical path and the side paths, the fights, gates and landmarks, time its pace, read what the designers said, and write down what works and why. The method behind the breakdowns in this part of the book.de_dust2: why the map has lasted for decadesBreakdownHow the most-played map of Counter-Strike is built: a simple figure eight, arches that split the map into places and cut sightlines, roads, trim and one sun for readability, a place for close fights and long ones, cover that favors one team in each phase of a round, and a bomb site rebuilt during testing.Dark Souls: a world that folds back on itselfBreakdownHow the first Dark Souls joins its world into one piece without loading breaks: a rough map before any art, a small shrine with ways out in every direction, shortcuts that bring the player back to it, a way down where home shrinks out of view, Anor Londo as a reward with no clear road, and what critics found missing.Hitman: Sapienza, a town built as a sandboxBreakdownHow IO Interactive built Sapienza: a coastal town that wraps around itself with no dead ends, six kinds of public and private space, disguises that give the player a role, targets kept on short routes after playtests, story threads that open a way in, and what the team itself thinks went wrong.