Law of Cartographical Elegance

"Law of Cartographical Elegance: The World Map always cleanly fits into a rectangular shape with no land masses that cross an edge."

- The Grand List of Console Role Playing Game Cliches, Rule #45

So you've gotten on the boat and want to explore the world. Perhaps you even brought a world map with you, and want to see where you're going before you actually get there. It's usually only a world map for the following reason: every land mass fits nicely within the square, never crossing the edges on either axis.

Since everything's placed in the center, the edges of the map serve one of two purposes:
 * Loops, where the player can travel to one end of the map and appear roughly on the same X- or Y-coordinate on the other side of the map. Topologically, this would mean the world is shaped roughly like a donut (In geometry, such a shape is referred to as a "Torus"). Or a cylinder if it only loops on one axis. Even so, this is merely part of the game's presentation, and none of these games are ACTUALLY supposed to take place on a toroidal or cylindrical world ).
 * Insurmountable Waist Height Fences that stretch to infinity, designed to confine the player within the boundaries of the game. These can be invisible, or defined by the game's topography if the "world" only consists of a single country or kingdom.

Seen in almost any video game that uses a World Map where the player can freely travel.

The world-maps at the front of many fantasy novels also obey the Law of Cartographical Elegance.

It should be noted that this trope can be blamed on actual maps of earth which also happened to be set up in such a way that the only land mass that actually crosses over the edges is Antarctica and the Chukchi Peninsula. In any case, an acceptable break from reality.

Subtrope of Video Game Geography.

Looping World Map

 * Also see World Shapes.

Platformers

 * The special stages in Sonic 3 and Knuckles, despite looking like a round world, are actually shaped like a torus that looks like a sphere that somehow has a curvature that suggests it's much smaller than it actually is.
 * Present in VVVVVV. Justified, since the whole dimension you are in is in shambles. As a result, it plays with the concept a bit by using the looping capabilities in unusual ways. In the middle is a tower which blocks horizontal progress; one has to loop to get from the left side of the map to the right (and vice versa). The tower, as an autoscrolling level, is actually 6 rooms larger than it seems from the outside. The laboratory section of the game is on the top and bottom parts of the left side of the map.

Role-Playing Games

 * The Final Fantasy games. (Except for II, where the map is still a toroid but a land mass actually crosses the edges. And Final Fantasy X where the world map is projected that way, but the airship doesn't fly freely around it.)
 * The Ultima games (In some installments. In others, the world literally is flat and rectangular, surrounded on all sides by an ethereal void).
 * The Tales (series).
 * Skies of Arcadia.
 * Chrono Trigger. Worse when during the ending you see the world as a globe under you.
 * Most of the Dragon Quest games (see exception below).
 * Final Fantasy Adventure is a torus with a land mass that crosses on both edges.
 * Justified in Shin Megami Tensei Nocturne, where the "Vortex World" is, essentially, the area along the inside of a giant sphere.
 * The original The Bard's Tale Trilogy. The guide for the second game refers to it as "wraparound magic".

Action-Adventure Games

 * Most games in the Zelda series are bounded by topography (usually mountains to the north and the ocean to the south). The Legend of Zelda the Wind Waker keeps you hemmed into the game world by having your boat forbid you to continue past the edges.
 * It also mentions that there's a storm (which you can see) further on. So, if you like, you can just imagine that the Wind Waker world is occasionally frequented by horrendously magnificent hurricanes, and that the game takes place in the eye of one.
 * Being that the world of Wind Waker only came about, that's not as far-fetched as one might believe.
 * Terranigma is an especially bad example, because the world is supposed to be, y'know, Earth.
 * Not quite an Insurmountable Waist High Fence in this case, though, so much as Insurmountable Mountain Ranges and Unmoorable Coastlines.
 * Justified in Beyond Good and Evil. After you pass a certain point, border police tell you to turn your vehicle back. If you ignore them, they open fire.

Driving Games

 * Motocross Madness had an Insurmountable Thirty Foot Fence around the arena, which was actually pretty easy to get over if you crashed into it just right and hit the recover button (in some versions, recovery occured automatical). You can then drive around the border of the arena, but if you drive too far away from it you get fired back into the center of the arena, painfully. Driving along it or even doing nothing doesn't help - sooner or later, you get kicked from the zone of nowhere whatever you do or do not do.
 * And awesomely.
 * Maps in the 4x4 Evolution series all have seamlessly looping edges, most often placed far away from the checkpoints of the race to give a better illusion of large, open spaces.

Role-Playing Games

 * The world of the Golden Sun series is flat, and you're not allowed to go over the edges.
 * Would you want to?
 * Yes! There's a Djinni down there.
 * Justified, as the edges of the map are quite literally the edges of the world due to the sealing of Alchemy/the Golden Sun/the Stone of Sages causing the planet to deteriorate. Everything beyond the edges of the map is presumably just empty void.
 * Well, empty void and the aforementioned Djinni. Incredibly creepy, though.
 * The first two and fifth Suikoden games all feature a limited game area in an (implied) much larger world. While the second and fifth game were better about using mountains and rivers, the first mostly relies on Great Wall of China-esque barriers.
 * In The Elder Scrolls III: Morrowind, the Island of Vvardenfell is supposed to be surrounded with a mile or two of water, but that same water seems to be infinite.
 * In Oblivion, when you reach the end of the map, a message appears saying that 'You cannot go that way. Turn back.' If, by modifying the game's settings, one walks over the border, there's a stretch of badly generated landscape, which ends in nothing.
 * In one of the series' spin-offs, Redguard, one could reach the edge of the map. There, a graphical glitch would cause the water to be shaped really odd. (This was referenced in one of Morrowind's books, where a character reaches the 'spiked waters at the edge of the map'.
 * Earlier, Daggerfall was borderless like Morrowind, and beyond the map was randomly generated terrain leading to nothing. No notice was given that the player was wandering outside the game territory, but a look at the map before even getting that far made it obvious.
 * Dragon Quest differs from the later games in the series in that all of Alefgard appears to be surrounded by water.
 * In the second game, it's revealed to be one of several "continents" in the game world.
 * Chrono Cross takes place in a small section of the Chrono Trigger world, so there's at least some reason. That, plus you never get an airship, and apparently there's only one strait that leads to the greater world, which conveniently has a strong current inwards, and your watercraft are never strong enough to go against it.
 * Justified in the first BardsTale RPG. You were trapped in a very square city.
 * The Wasteland RPG featured this. Trying to go past the map's edges caused a comment about the irradiated wasteland beyond and the notion that you wouldn't survive it.

Simulation Games

 * In Doshin the Giant, it is possible to walk off the edge of the world.
 * Drakengard.
 * The world maps (which are actually very large islands) in Operation Flashpoint work this way. Each one is bordered by endless ocean, much like the Grand Theft Auto games but without the invisible barriers out to sea. If you do insist on flying out into the ocean, you just end up off the map and hopelessly lost.

Tabletop Games

 * Creation in Exalted. Like the Ultima example given above, this is because Creation is literally flat and (roughly) rectangular; the Insurmountable Waist Height Fences are the Elemental Poles of Air, Wood, Fire, and Water, beyond which lie the formless chaos of the Wyld.

Wide Open Sandbox

 * In the Grand Theft Auto games, Liberty City consists of 2 islands and a peninsula with mountains separating it from mainland, Vice City is made of 2 long, parallel islands, and the state of San Andreas is pretty much a huge, neatly formed square of land.
 * Out in the middle of nowhere, too. Try flying just straight north/west/south/east. You'll run out of attention span (and maybe trigger a few glitches) before hitting a barrier, I think.
 * If you sail out far enough in SA and try to swim back you can actually be blocked by an invisible wall from getting back to land.
 * In Mercenaries: Playground of Destruction, the main game takes place on 2 maps in North Korea, both of which form a perfect square. The player cannot normally reach the boundaries though because passing into a red zone (which surrounds the map a good distance from all edges) will cause the Allies to bomb them until they die. One can reach the edge though certain means, though. Each "Ace" has their own island separate from the main maps, where the same rules apply.
 * Perhaps an Egregious example would be in Prototype, where even the real life location of Manhattan is rendered into a more rectangular shape by shaving off the entire portion north of 129th Street.

Adventure Games

 * Discworld II: Missing Presumed..., where, of course, the world really does have an edge.

Four X

 * In all of the Civilization games (and the spinoff Alpha Centauri), the worlds are cylindrical: you can circle endlessly east and west, but north and south you are blocked by "the poles". You can, however, enable an option that allows you to build flat worlds.
 * The Activision clone Civilization: Call to Power allowed a 'Donut-shaped World' option in world generation.
 * Civilization IV also allows donut worlds, as well as ones that wrap north-south, in addition to the traditional east-west wraps and flat worlds. It also has a zoom-out function for the standard cylindrical map that makes it look like a globe with very large impassable polar caps.
 * Spore averts this with looping on the X axis, no looping on the Y axis and faster movement on the X axis as you get closer to poles to represent the distortions caused by the projection.

Miscellaneous Games

 * Katamari Damacy and its sequels are partial aversion. At the lower sizes the world is restricted by Waist High Fences. At the second highest size it is the classic toroidal shape, with the katamari, teleporting to the other side of the map in mist. At the highest size the Katamari rolls over a proper globe.

MMORPGs

 * Azeroth of World of Warcraft masquerades as a globe. Swimming brings you death, but it is theoretically possible. Outland is a perfect example of this trope, since it's a magically shattered remnants of a planet set in the 'Twisting Nether" where physics do not necessarily apply.
 * Sometimes, Good Bad Bugs allowed one to reach the far outside border of one of the continent maps. There's a massive strip of land out in the middle of the ocean that denotes the edge of the game world for each continent.

Platformers

 * Round worlds are commonly seen in every Ratchet and Clank since the second one, though they're not very big worlds, about the same landmass as a regular level.

Real-Time Strategy

 * Populous: The Beginning is a RTS from 1998 with with planets instead of maps, meaning that every world you fight on is round. If you zoom out, you'll see half the world. You can never see the entire world in one screen, but you can scroll in any direction. Your units can move in any direction as well. For a RTS this is quite remarkable.

Role-Playing Games

 * Most of the Might and Magic games have worlds that are literally flat and rectangular. There's no fence at the edge, so if you're not careful you can walk right off into outer space.
 * Final Fantasy VIII is a double subversion: if you orbit around the globe at an angle to the map, you'll notice that it doesn't match properly. The map simply doesn't make sense unless the world is a toroid.
 * Final Fantasy XII is the only exception in the Final Fantasy series so far. While the world map isn't freely navigable there's no indication of it looping.
 * Its sequel Final Fantasy XII: Revenant Wings, however, fits this trope.
 * In both versions this is justified since the games take place in only a portion of the greater world of Ivalice and the map only covers that portion.
 * Wild ARMs: Alter Code F has a huge if narrow piece of land that extends through most of the vertical part of the map and wraps from bottom to top.
 * The world in Secret of Mana actually is spherical. It rotates normally on the X-axis, but if you fly along the Y-axis long enough, you'll eventually see some of the countries scrolling by upside-down. Interestingly, this makes it harder to navigate since most players aren't used to viewing game worlds that way.

Turn-Based Strategy

 * Averted entirely in UFO:Enemy Unknown (aka X-COM), which has a nice rotatable round map.