User:MentalMouse42/Overview

This is meant to be an overview of Minecraft, not from the pure newbie's or munchkin's point of view, but for someone who thinks of games in terms of structure and balance.

Basic structure
Minecraft is a hybrid game. Its original form was as a "sandbox" game, in which the player has pretty free reign to manipulate the world. However, it has since acquired an "adventure" component as well, in which the player is confronted by both the need (or desire) for certain resources, and hazard from various threats. There are three major game modes, each of which offers different emphasis on these two aspects of the game. Any of these modes can be played in single-player or multi-player modes. There are also both built-in features ("flatworld") and external "game mods" which can drastically change gameplay; I will not be discussing these.

World Structure
All the game modes share the same basic world structure: A grid matrix of cells (in-game, "blocks"), which is finite vertically, but which is automatically extended horizontally as the player(s) move about. In general, this generation happens far enough from the player to be invisible to them, though a rapidly travelling player might notice some related anomalies.

Each of these blocks can be empty ("air"), can be filled with some material, or contain an object ("item block"), which is usually connected to one or more adjacent blocks. There are also "entities", objects which may move across the grid, and (unlike blocks) are usually not limited to integral coordinates. These entities include the player, "mobs" both hostile ("monsters") and friendly, occasional vehicles, and "item entities" representing blocks and items which have become detached from the matrix proper. (There are a few immobile entities which are also fixed to the grid.) The player can convert blocks into items, and collect them in the inventory for later use. The player can do various things with items: most can be placed into the world, many can be converted into different items, and some consumed directly by the player. The inventory is large, and there is no encumbrance mechanic.

Game Modes
Creative mode is the purest expression of the "sandbox" aspect of Minecraft: Resources are infinite, obstacles can be wiped away easily, and the player not only invulnerable, but has total freedom of action, including access to many "internal" game commands for manipulating the world. In this mode, players can create huge and complex structures, or experiment with the subtleties of game mechanics. Creative mode also doubles as the "build" mode for creating "custom" maps, which can be copied for use by other players.

Survival mode represents a balance between sandbox and adventure aspects, somewhat biased toward the sandbox side. The prospect of injury and death appears, and also the need for food. These are represented by health and hunger "bars" (gauges) respectively. However, most hazards are avoidable, and food is plentiful. Death results in being respawned at a fixed or previously-chosen location, while the player's items remain at their death location (where they can be lost or destroyed). Environmental hazards also appear, notably monster attacks, falling, drowning, and burning. The level of hunger affects healing: near-complete satiation allows injury to heal over time, while starvation inflicts damage. Nearly any block or object can be destroyed, but some require special tools to collect them as items. Several difficulty levels vary the level of hazard, and add or remove various dangers, including making exceptions to the above. To summarize the difficulty levels:
 * Peaceful: No monsters are present, and food is not necessary for healing.
 * Easy: Monsters appear, but with weak attacks.  Starvation will reduce the player to at worst half their maximum health.
 * Normal: Monsters attack at nominal strength, and some have special attacks.  Starvation and poison can reduce the player to minimum (non-fatal) health.
 * Hard: Monster attacks are more powerful, and starvation can kill the player outright.
 * Hardcore mode: Identical to hard mode, but the player does not respawn upon death.  That is, death is a true "game over".

Adventure mode shifts the game strongly toward the "adventure" aspect of the game. Play is always, or at least begins, on a previously prepared map, rather than on the randomly generated and unlimited map of the other modes. Similarly, destruction and collection of blocks is more tightly limited. The map provides various constraints, resource limits, and objectives, and can apply special rules or responses for player action.

Of these modes, Survival at Normal difficulty represents the "canonical" Minecraft experience, and most of the following discussions of balance and game structure will refer to this mode. (While Creative mode is popular for artistic efforts, game balance and structure hardly apply to it.)

The Gameworld
There are actually three separate grids ("dimensions"), but two of them represent advanced segments of the game. The primary dimension or Overworld is 256 blocks high, bounded above and below by regions which the player cannot affect or (normally) enter. The top half of this range, however, is not populated by the game engine, and represents space for player constructions. This gameworld mimics a natural terrain, with pseudorandom variation providing a variety of environments ("biomes") -- these vary not only in appearance, but in available resources, and in some cases, game-rule modifications. The bottom quarter of the height range is occupied by oceans and the underlying mass of the terrain, the latter riddled with caves and other gaps.

There are some global processes which occur occasionally, and simultaneously across the gameworld, but otherwise, the world is essentially static, with significant change introduced only by the player. However, parts of the gameworld can be created in unstable states, leading to changes happening shortly after generation. Due to performance considerations, all gameworld changes are limited to a certain range ("chunk update radius") around the player(s), including those processes previously begun by player action.

Discussions from this point on will increasingly refer to specific elements and contents of the gameworld.

Global Processes

 * The most prominent global process is the day/night cycle, which repeats every 20 minutes of play time. Night time reduces light levels, which affects not only in-game visibility, but the monster generation process described below.
 * There is also a pseudorandom variation in "weather", among "clear" weather, "rain", and "thunderstorm". The latter two impede visibility in their own right, and also reduce light levels, which again affects monster generation.
 * Thunderstorms also produce lightning, which produces a rare hazard for players, and also occasionally sets small fires on the landscape.
 * In desert biomes, neither rain, snow, nor lightning falls, but the reduction in light levels still occurs.
 * In "icy" biomes, rain and thunderstorm are replaced by snowy equivalents, which can deposit snow on the landscape and freeze surface water. This can set off other processes, mostly killing certain plants.
 * While most peaceful mobs are created with the terrain, a few are spawned afterward. Most require a minimum light level, so appear on the surface during clear days.
 * The only water mob (squid) is created in oceans as an ongoing process.
 * Hostile mobs, or monsters, are generated differently. They are created continuously, but only in darkened spaces.  Thus, they can always appear in underground caves, but on the surface they will appear primarily at night, and occasionally during thunderstorms.  This "natural monster spawning" only occurs within a certain range of some player (but is suppressed very close to them), and hostile mobs tend to despawn outside a somewhat larger range.
 * Some of these monsters (zombies, skeletons) are specifically destroyed by bright (clear-weather) sunlight, while others (spiders, Endermen) are "defused", becoming non-aggressive.
 * One type of monster (Endermen) makes occasional minor alterations to the gameworld, when present.
 * As noted above, parts of the landscape can be generated in unstable states, beginning processes which will proceed as soon as the player comes within update range of the area. These include:
 * Newly generated springs of water or lava will flow. They may form obsidian, stone, and/or cobblestone as water and lava interact.  Ocean or lake blocks may also flow into available openings to underground spaces, with similar results.
 * Some leaf blocks are generated in inappropriate places, and will die within a few minutes, perhaps dropping sapling items.