How to design dungeons from locks and keys

1 The bottom line

Draw your dungeon as a graph of keys, locks and backtracking, then move keys, locks and choices to set how linear it feels. The graph shows where players really return, which a key count never does.

2 Key takeaways

• Draw the dungeon as a graph before you judge it. A graph lets you compare layouts objectively instead of just counting keys.
  • Oracle of Seasons' first dungeon, Gnarled Root, needs Ember Seeds to light lanterns and open locked doors on the way back, and the graph shows that return trip Mark Brown, Game Maker's Toolkit1:54.
• Place each key and lock to control distance and memory. Distance sets difficulty, and nearness spares the player's memory.
  • In Metroid Dread, 13 of the 22 abilities are used in the biome where they are found Mark Brown, Game Maker's Toolkit5:26.
• Add real choices to open the dungeon up. Choice of keys, doors and branches is what separates open from linear.
  • Palace of Darkness is the first A Link to the Past dungeon where you hold more than one key, so you pick your route and hit fewer dead ends Mark Brown, Game Maker's Toolkit3:42.
• Make backtracking something the player works out. Return trips only reward players who must find where the item applies.
  • Link's Awakening scatters holes, heavy pots and deep water, so one item changes the whole dungeon in an instant Mark Brown, Game Maker's Toolkit3:25.
• Vary the shape from dungeon to dungeon. A good structure repeated too often costs the sense of growth.
  • Six of Twilight Princess' dungeons share one knotted structure, with Goron Mines and the final dungeon as exceptions, so they show no progression in complexity Mark Brown, Game Maker's Toolkit2:16.

What it's about is asking whether the way forward is always directly in front of the player

Mark Brown, Game Maker's Toolkit

2.1 Draw the dungeon as a graph

Before you tune anything, map the keys, locks and returns so you can see the shape you have built.

• Draw the graph as key item, small keys, locks, backtracking, then boss key and boss door, as in Mark Brown, Game Maker's Toolkit1:54.
  • Lay the graph over the floor plan to see spacing and complexity.
  • Let each section stand for the rooms reachable before a given door is unlocked, so you can see when a key item or boss key forces a return Mark Brown, Game Maker's Toolkit4:59.
  • The Wind Waker's Earth Temple graph shows almost no reason to go back once a door is unlocked, while the Wind Temple graph shows many Mark Brown, Game Maker's Toolkit4:59.
• Sort the dungeon as lock and key, puzzle box or gauntlet before you design it, following Mark Brown, Game Maker's Toolkit6:08.
  • Lock and key dungeons are mazes cut off by padlocked doors, and you untangle the knot with keys.
  • Puzzle box dungeons make the architecture the puzzle, and gauntlets are linear and focus on puzzles and fighting.
  • Ocarina of Time has all three: Forest Temple is lock and key, Water Temple is puzzle box, Shadow Temple is gauntlet.
• Place the dungeon on a find-the-path to follow-the-path scale with four questions from Mark Brown, Game Maker's Toolkit6:36.
  • Ask whether there are branching paths, whether the player chooses the sequence, whether there is backtracking, and whether the player does that backtracking themselves.
  • Mostly yes makes a find-the-path dungeon, and mostly no makes a follow-the-path dungeon.
  • The Minish Cap's Fortress of Winds answers yes to all four, and Palace of Winds answers almost no to all of them.
  • A Link Between Worlds passes the lock and key test of multi-exit rooms, pocketfuls of keys and button-driven backtracking, and uses no shortcuts that do the backtracking for you Mark Brown, Game Maker's Toolkit8:07.
• Plot a dependency graph to read how linear or open a whole world is, as Mark Brown, Game Maker's Toolkit6:35 does for Metroid.
  • Short and wide means many branches and lots to do at once, and tall and thin means a nearly linear path.
  • Use diamonds for upgrades, squares for the obstacles they beat, triangles for optional pickups, and dotted lines for locks you can see but cannot yet beat Mark Brown, Game Maker's Toolkit4:15.
  • Metroid 1 comes out short and wide, and Zero Mission comes out tall and thin.
  • Super Metroid's graph grows from a few branches into a wide spread after Crateria reopens Mark Brown, Game Maker's Toolkit4:15.

2.2 Place keys and locks

Where you put a key relative to its lock sets difficulty, memory load and how often players get stuck.

• Move a key farther from its door to add challenge without changing the door Mark Brown, Game Maker's Toolkit2:37.
  • A key forces the player off the critical path to find it before the door opens, so more distance means more exploration.
  • Gate the final door on a key count you can change, since one number rebalances how much of the game players must finish Mark Brown, Game Maker's Toolkit5:38.
  • In Mind Over Magnet each level holds one key, and a progression manager saves them and opens the hub's final door at a set number.
• Put the lock near its key, and give each key very few locks, as Mark Brown, Game Maker's Toolkit6:49 describes in Metroid Dread.
  • A lock you visited recently is still in working memory, while rooms from the start are forgotten Mark Brown, Game Maker's Toolkit5:26.
  • Fewer locks per key means less to remember and an easier time finding the correct path.
  • Reserve many-lock abilities, like the grapple beam, for optional pickups.
  • After the Plasma Beam, only one door in the whole world is behind a plasma shield, and it is the next place you need to go.
  • Hollow Knight's Desolate Dive opens many floors, and only one of them matters.
• Keep small keys inside the dungeon, and make required progress depend only on what the dungeon provides Mark Brown, Game Maker's Toolkit3:11.
  • When a key opens any door in the game, players arrive with too many keys or too few.
  • Self-contained dungeons let you control exactly how many keys exist.
  • Zelda 1 Level 6 gives one key and two locked doors, and one leads only to a hint room, so a player with no spare keys is stuck.
  • Zelda 1 patches the shortage with an expensive shop key, which feels like a messy fix when rupees are scarce Mark Brown, Game Maker's Toolkit2:58.
• Gate the boss room behind the dungeon's item, and never hide critical-path walls, advises Mark Brown, Game Maker's Toolkit4:13.
  • If a required item can be missed, players find out much later, far from where it was. Optional upgrades can stay skippable.
  • Bombable walls that look like normal walls are fine for optional secrets, but maddening on the critical path Mark Brown, Game Maker's Toolkit6:02.
  • In Zelda 1 you can miss the Level 1 bow and not notice until Level 6, where arrows are needed for the spider boss. Level 4 fixes this with water crossed only by the stepladder, and Link's Awakening made it the rule.
  • Zelda 1 dungeon 7 makes you blow holes in four walls to reach the boss, and the first room is not even on the map.

2.3 Tune how linear it feels

Forks, spare keys and door choices open a dungeon, and chained locks close it.

• Fork the path so the player must explore and later come back, as in Mark Brown, Game Maker's Toolkit3:50.
  • A fork leaves the other branches behind the player, so they return once they find a key, item or switch. A branch that is a dead end for now still counts.
  • Open a large explorable area before the first lock to make the dungeon feel large and maze-like Mark Brown, Game Maker's Toolkit3:54.
  • Fortress of Winds forks early, and the right-hand door leads to a mud room that cannot be crossed until the Mole Mitts are found on the left.
  • In Unicorn's Cave you can explore a huge part of the dungeon before opening a single door.
• Let players find several keys at once, or choose between locked doors, as in Mark Brown, Game Maker's Toolkit3:27.
  • If the graph shows more than one key reachable at once, the player picks the order, which costs little.
  • Give two doors to pick from even if the same key is needed eventually, because it stops the dungeon feeling so predetermined Mark Brown, Game Maker's Toolkit3:37.
  • Oracle of Seasons' Dancing Dragon Dungeon lets you find multiple keys at one time.
  • Oracle of Ages' Wing Dungeon has one door leading to the boss key and another to the boss door.
• Make each choice lead somewhere different, and do not put every locked door behind another, warns Mark Brown, Game Maker's Toolkit2:40.
  • When each locked door sits behind another, the route is forced and the dungeon is cut into small chunks. A Link to the Past and Link's Awakening let players pick doors instead.
  • A choice only counts if the paths differ Mark Brown, Game Maker's Toolkit3:15.
  • Ocarina's Fire Temple has two keys for two locks, and the order changes nothing, so it is not a super exciting decision.
  • Ocarina's Shadow Temple and Spirit Temple open piece by piece, each key fitting one door until the boss.
  • Metroid Prime 3 offers Bryyo or Elysia, but Elysia stays locked until you beat Bryyo's boss and get the Hyper Ball, so it is no choice Mark Brown, Game Maker's Toolkit5:25.
• Make some keys and upgrades optional so players choose their route, as in Mark Brown, Game Maker's Toolkit10:57.
  • Let players start the key hunt early and finish with only a subset, so those who want to finish can, and thorough explorers are rewarded.
  • Hide the optional keys among the required ones, because players cannot tell which doors are optional Mark Brown, Game Maker's Toolkit10:42.
  • Prime 3 needs only 5 of 9 energy cells, and the first is available on Bryyo with few items owned. Prime 1's artifacts and Prime 2's Sky Temple Keys forced a full world sweep late.
  • Metroid 1's Varia Suit, Long Beam, Screw Attack, Hi Jump Boots and Wave Beam are all skippable Mark Brown, Game Maker's Toolkit5:50.
  • Prime's 17 upgrades come in a set order, but its 12 Chozo Artifacts can be found in any order Mark Brown, Game Maker's Toolkit11:48.

2.4 Make backtracking worth the trip

Players should return because they noticed an obstacle and worked out what solves it.

• Let one item open obstacles scattered across the whole dungeon, as Mark Brown, Game Maker's Toolkit3:25 shows in Link's Awakening.
  • Seen-but-blocked places motivate the return, and the dungeon changes in an instant when the item arrives.
  • Give the item many uses, so the dungeon is recontextualised like a mini Metroidvania Mark Brown, Game Maker's Toolkit4:01.
  • Tail Cave has holes for the Roc's Feather, Bottle Grotto has heavy pots for the power bracelet, and Angler's Tunnel has deep water for the flippers.
  • Ocarina uses the boomerang, bow, longshot or hammer on earlier obstacles in four dungeons, while the Deku Tree and Shadow Temple give the item too early for any backtracking Mark Brown, Game Maker's Toolkit4:11.
• Do not hand the player a direct path back to where the new item is needed Mark Brown, Game Maker's Toolkit2:00.
  • Backtracking only rewards the player if they have to work out where the item applies.
  • Put a needed key behind a spot the player cannot yet reach, so every player sees the backtrack point Mark Brown, Game Maker's Toolkit4:54.
  • Wind Waker's Forbidden Woods opens a door right outside the boomerang that leads straight back to the flower room. Dragon Roost Cavern, Tower of the Gods and Earth Temple do the same.
  • In Twilight Princess' Forest Temple a bridge faces the wrong way, and the Gale Boomerang later twists it.
• Make a switch change the dungeon somewhere other than where you flip it, as in Mark Brown, Game Maker's Toolkit2:03.
  • Force the player to leave the room, change the state and come back, so they build a mental map Mark Brown, Game Maker's Toolkit3:32.
  • Put the switch in a different room from its effect, so the player must predict what it does Mark Brown, Game Maker's Toolkit9:33.
  • In the Water Temple a lever shoots water under your feet and raises the level in a far room.
  • A cracked Water Temple wall cannot be bombed underwater, so the water must be lowered to floor two elsewhere first.
  • The Sandship's single timeshift stone sits on the deck while its effects are felt in rooms below.
• Cut dead backtracking that teaches nothing Mark Brown, Game Maker's Toolkit12:29.
  • Let players teleport out of the dungeon after the boss.
  • Stack several locks at one door only when players are not nudged to return early Mark Brown, Game Maker's Toolkit16:23.
  • Prime 2 makes you power up reactors in the Dark World, then the Light World, then walk to the main temple, and Retro forgot to borrow Zelda's instant exit.
  • Super Metroid's Ridley's Lair needs a power bomb, then the gravity suit, then the space jump, so a player who returns after each one leaves disappointed twice.

2.5 Shape the whole dungeon

Size, flow and mix decide whether a good key and lock structure feels good over a whole game.

• Keep the dungeon small enough to hold in the head, and chunk it around a hub, say Mark Brown, Game Maker's Toolkit7:57.
  • A cognitive map only works if the player can remember the entire space. Oversized or cluttered dungeons break it.
  • Split the dungeon into wings finished in isolation, so finished chunks can be ignored and the central room keeps the long-term goal in view Mark Brown, Game Maker's Toolkit2:40.
  • Forest Temple, City in the Sky, Arbiter's Grounds, Lakebed Temple, Snowpeak Ruins and Palace of Twilight all send you back to a central room three times.
  • Lakebed Temple's hub is itself a puzzle, a staircase that rotates in 90 degree notches and sends water to a far waterwheel Mark Brown, Game Maker's Toolkit5:37.
• Hide a single critical path with detours, and judge linearity by what is ahead, as in Mark Brown, Game Maker's Toolkit3:05.
  • Optional rooms, one-way block paths, keys that pull you off the path and a route that loops back over itself make a guided path feel self-made.
  • A dungeon is not linear just because events happen in a fixed order. It feels linear when the next step is always directly ahead and earlier areas stop mattering Mark Brown, Game Maker's Toolkit4:06.
  • Eastern Palace has one real path, with boulders, a big loop to the big key, then backtracking to the giant chest.
  • Wind Waker offers only one key at a time, and Earth Temple lets earlier areas disappear. The Wind Temple reuses its space behind the hookshot, the fan and rescuing Makar, so the next step is not always in front of you Mark Brown, Game Maker's Toolkit5:26.
• Alternate tight linear stretches with open branching ones, as Mark Brown, Game Maker's Toolkit2:54 finds in Dark Souls.
  • Acts 1, 3 and 5 are linear with forward momentum, and acts 2 and 4 are open and branching. A Link to the Past uses the same accordion outline.
  • Loop the world back on itself with one-way doors and shortcuts, so players are not overwhelmed early and the world grows more complex Mark Brown, Game Maker's Toolkit6:54.
  • Dark Souls' Firelink Shrine later links to the Undead Parish and Lower Undead Berg once you open a locked aqueduct door from the other side.
  • Breath of the Wild's divine beasts are almost entirely open and lack memorable flow, and Vah Ruta is the exception with its water wheel and climb Mark Brown, Game Maker's Toolkit12:05.
• Mix micro challenges, navigation and combat so no one thing carries the dungeon, say Mark Brown, Game Maker's Toolkit0:15.
  • Small fights and block puzzles keep players busy while they solve the macro problem of reaching the boss. Dungeons with only micro challenges feel like a sequence of rooms.
  • Puzzles alone leave dungeons short and flat Mark Brown, Game Maker's Toolkit9:44.
  • Skyward Sword's Earth Temple and Fire Sanctuary are simple at the macro level but rich in micro mechanics.
  • Breath of the Wild's divine beasts have no keys, no locks and almost no combat, only a few guardian scouts, floating skulls and one boss.

2.6 Where designers disagree

Some tactics trade against each other, and some only fit certain products.

• One item with many uses reshapes a dungeon, but one key with few locks is easier to follow.
  • The fire rod or Pegasus boots bypass many obstacles, which gives the player more to think about and remember Mark Brown, Game Maker's Toolkit4:01.
  • Metroid Dread gives most power-ups one obvious place to use them, so the player has less to remember Mark Brown, Game Maker's Toolkit6:49.
  • Many-lock abilities fit best on optional pickups, which gives both goals a home.
• Open item order frees the player but costs puzzle depth.
  • Renting items from Ravio removes the loop of blocked path, item, return, and only the Desert Palace keeps it Mark Brown, Game Maker's Toolkit3:45.
  • In open-order games a dungeon can only feature puzzles for the one item the player must hold Mark Brown, Game Maker's Toolkit4:55.
  • Swamp Palace in A Link Between Worlds can use the hookshot but not the boomerang, bow, hammer or any other tool.
• Free movement and lock and key design do not mix well.
  • Jumping and gliding mean areas need not be sealed by doors, which makes older dungeons feel stiff Mark Brown, Game Maker's Toolkit5:19.
  • Puzzle box dungeons need heavy restrictions and hand-crafted solutions, so loose movement lets players cheese them Mark Brown, Game Maker's Toolkit14:47.
  • In Tears of the Kingdom you can phase through the floor and skip half the puzzles.
• Linear is not automatically worse than open.
  • Most Majora's Mask dungeons are linear, and their complexity comes from asking the player to work out the architecture Mark Brown, Game Maker's Toolkit8:07.
  • Super Metroid's fixed late boss order is a missed opportunity, though linearity is not necessarily bad Mark Brown, Game Maker's Toolkit19:21.
  • Great Bay Temple needs you to link the red valves to the water wheel, and Woodfall Temple needs you to raise a platform to reach a door.