last month i met with charles pratt of game design advance to record a conversation that should hopefully be available for to insterested eavesdroppers sometime soon. one of the subjects we discussed is the stupifying lack of discussion, decades after people started piecing together digital games, on the art and craft of level design. a week ago, playing through satoru okada’s super mario land for the gameboy, i realized i could probably teach level design just using scenes from that game.

here’s one. this area (click here for a bigger image) appears halfway through super mario land’s stage 1-3, the third stage of the game[1]. numbers in brackets indicate footnotes, by the way.

crucial to this example are two rules of super mario land that a player who approached the game in 1989 after having played the original super mario bros. would have immediately understood.

the first is that mario has two states[2]: “little” mario and “big” mario, the former of which can transform into the latter by finding a magic mushroom. little mario is as tall as a single game block; big mario is as tall as two, making him slightly more susceptible to danger: if big mario comes into contact with an enemy, he’ll revert to little mario. unlike little mario, big mario has the ability to break certain blocks (the light gray, rounded ones in the above picture) by jumping at them from below.

the other relevant rule is that the screen only scrolls to the right. while mario can move freely towards the right, where his goal is, he’s only allowed to retrace his steps as far as the player can see: the left edge of the screen acts as an immovable wall that follows mario through each stage.

halfway through world 1-3, the first “indoor” stage of the game, the player is given a choice. the path rightwards splits into three routes - up, middle and down - though the choice is in fact between only two of them: either of mario’s states makes one of the routes inaccessible. the upper route is blocked by bricks that only big mario can break by hitting them from below. the lower route’s entrance is only one block tall - little mario alone is short enough to enter.

this is interesting because little mario is, most of the time, an undesirable state to be in. little mario can’t break blocks, is only one hit away from death, and must find two power-ups to be able to wield the “superball” weapon[3]. here, mario is given access to a special place as a kind of compensation for this otherwise weaker state - and the bottom route is in fact the most lucrative of the three.

but note that it’s not obvious to a first time player that the bottom route has the best outcome, because at the moment of the player’s choice the screen hasn’t scrolled far enough to the right to reveal the horde of coins. because the entire height of the stage fits the height of the screen, though, a player on the upper route will see the treasure she’s missed. this helps to mitigate the frustration of losing a life against the tough enemies to come: starting over halfway through the stage - and mario returns as little mario, regardless of what state he died in - means an opportunity to nab the coins i saw earlier.

also note that there are no enemies right before the junction: you don’t get to choose which state mario’s in when the path splits. there’s a single enemy on the upper route, behind the bricks, so an experienced player - or clumsy one - can smash her way up to the top, be shrunken to little mario by the enemy, and then double back to the lower route. there’s just enough room between the edge of the screen and the entrance if the player knows what she’s doing.

let’s talk about the way the treasure room is put together. that ? block contains a magic mushroom: in addition to snagging up to thirty-eight coins, the little mario who enters the chamber will exit as big mario. the player must become big mario to leave: those two grey breakable bricks, floor to a mario above but smashable to a mario below, serve as a one-way passage, letting mario out but not in.

so what’s that tiny pit on the right for? it’s for mario if he misses the mushroom. only big mario can leave this chamber - can’t go back left! - and if little mario were to miss the mushroom, he’d be stuck with no escape but to wait for the time limit to tick down and kill him. or to jump in the pit; note that the entrance is only one block tall.

it’s incredibly unlikely that the player should miss the mushroom, of course. see that little block sticking up out of the floor on the left? that block serves two purposes. when the mushroom pops out of the ? block and flies through the air, it’ll hit the wall and turn around; when it reaches the floor, it’ll start moving to the left. that little block knocks it back toward the right, both preventing it from disappearing off the left edge of the screen (a wall to mario, but not to the mushroom) and making its journey to the pit longer, giving the player more time to nab it.

so why have a pit at all? why not just have the mushroom bounce back and forth between two walls until the player catches it? because it’s sloppy. because the threat of potentially losing that mushroom - even if it’s unlikely - makes it far more valuable. because challenge and momentum are both big parts of super mario land, and a time-sensitive situation reminds the player of this.

on the subject of challenge, three of the ceiling bricks above the treasure room fall when mario gets near, potentially hurting him. because they fall the entire height of the screen, they’re a hazard to mario regardless of whether he’s in the treasure chamber or above it. but since they fall from the top of the screen, a mario above the chamber is naturally in greater danger of being hit than one inside the chamber. a mario above, however, is also more likely to be a big mario, while a mario below is definitely a little mario.

the treasure chamber mitigates the frustration of death in a boss level by giving the player a chance to visit a different route (and remember, those are thirty-eight of the hundred coins required for an extra life); it prepares the player for the boss by leading her towards a room that ensures mario’s in his big state; it gives a meaningful play context to the difference in size between mario’s states that is so central to the game and its protagonist. what other purpose does it serve?

it’s a pyramid! this stage is intended to remind the player of an egyptian tomb - you can see pixel hieroglyphs on the walls and big stone bricks[4]. what better way to evoke the idea of a pyramid than by letting the player enter one in the stage itself - one that’s full of treasure and has a secret entrance, no less. you can see that the hollow treasure pyramid is almost immediately prefigured by a solid block pyramid, too; pyramids like these appear throughout the birabuto kingdom, the game’s first three stages. a pyramid the player can enter, then, is the culmination of a recurring level design motif.

all the goals that this “setpiece” accomplishes - and good level design often accomplishes several things simultaneously - it does so using a handful of basic building blocks that are already known to the player: solid blocks, breakable blocks, and ? blocks. concise design doesn’t introduce new game elements needlessly: an element that the player’s already encountered already has meaning to her, and she understands its implications.

this is good level design.

[1] the game’s first world, the birabuto kingdom, most closely resembles the structure of the original super mario bros.’s worlds - a ground stage, a treetop stage, and a castle stage, culminating in a fight with a villain over a pool of fire - to present something familiar to super mario bros. players before the greater digressions of the later stages.

[2] technically three (not counting mario’s submarine and airplane), but superball-throwing mario behaves the same as “big” mario for the purposes of this example.

[3] not just a weapon: mario land’s superball, unlike super mario bros.’s fireball, has the additional ability to collect coins it touches, extending mario’s reach much as the magic mushroom does.

[4] not visible in the image are the stage boss and its minions. they’re sphinxes.