Debug mode



Debug mode is a world type used to test block models, states and textures. It is thereby useful not only to Mojang developers but also to creators of resource packs.

Accessing
To select the debug mode, hold the key while clicking the "World Type" button. Debug mode will then be the world type directly after Customized, and just before Default.

Upon selecting debug mode, the "Bonus Chest", "Generate Structures", and "Allow Cheats" options are removed from the menu. The game mode is set to Spectator, and the difficulty is locked on peaceful; however, and  will work as usual within the world.

Properties


Debug mode contains all Minecraft blocks in all their different block states in a single world, in a grid across height y=70, with a barrier floor at y=60. Every block state generates only once. The remainder of the map is empty.

Breaking any block, including those in the barrier floor, is impossible in this mode. Likewise, placing blocks is impossible, and the commands, and  are unavailable. Some blocks allow right-click interactions (e.g. chests, beds, cake, and generally speaking, those interactions which do not change any block state), while others do not (e.g. levers, redstone repeaters). A block's state cannot change, but its block entity data can change, for instance through using or through normal player interaction. When is used, the FallingSand entity instantly despawns.

The block grid is approximately 144×148 in size, occupying the +X,+Z (southeast) quadrant, although the barrier floor extends past the grid in all directions to the world border. Starting at 0,0, the blocks are arranged first in rows of 74 block states from north to south, then in 72 rows from west to east (with an additional partial row of 18 states), following first the numerical data values of the blocks, then the block state names and values in alphanumeric order. The southernmost (74th) column contains duplicates of 72 states from the northernmost column. There are 5,274 unique block states.

Issues
Note that any bugs relating to using other game modes than spectator are resolved as invalid due to the fact that the world type can only be legitimately accessed in spectator.

Trivia

 * The biome is plains (except when in the Nether or the End).
 * The sun is displayed as if it were the beginning of day (time 1000), but there is no day/night cycle. The daytime can be adjusted, and the day/night cycle can be toggled as usual using console commands. The time can be advanced to sunrise by using a bed.
 * In game modes which normally allow blocks to be broken, if the player attempts to break a block, all the usual signs will occur – the player's arm swings, cracks appear, and block-breaking particles spill out – except that the block remains unbroken.
 * Water and lava cannot be removed by buckets, but will fill an empty bucket in survival mode.
 * Cauldrons will clean leather armor and banners, but cannot be filled by buckets.
 * All blocks with inventories are usable.
 * Either TNT block will drop a primed TNT when activated by flint and steel.
 * a button or lever will drop one of itself as an item.
 * Activating those blocks schedules a block tick for its own block, which drops one of itself because those blocks cannot be suspended in mid-air.
 * an unactivated pressure plate will cause it to generate enormous quantities of dropped plates, make weird noises, and likely crash the game.
 * The pressure plate schedules a block tick for itself, which drops an item because it cannot be suspended in mid-air.
 * Since it never changes to an activated pressure plate, it never stops receiving activation from the entity or the items on it, and never stops scheduling block ticks.
 * Certain pressure plates, when activated, cause an error in the game output, stating that the dropped item entity has no entity.
 * a comparator in subtract mode, a lever or an unpowered button will cause the block in the direction opposite its  property to drop as an item.  If that block is a repeater or a comparator, it will drop 36 stacks of itself.
 * These types of blocks schedule a block tick in the adjacent block.
 * If that block could not normally remain suspended in the air, it will drop one of itself as an item.
 * If it is a repeater or a comparator, it will start to repeatedly schedule its own block-state-changing tick, which will fail continually a large number of times.
 * Rails and minecarts operate as usual.
 * Certain glass panes, iron bars and fences have incorrect hitboxes.
 * Banners are entirely invisible.
 * If you open or close the doors or trapdoors, they will not move, but you will still hear the sound.
 * If a Nether or End portal is used, the player will spawn in a Nether version or an End version of the debug world, respectively. The sky, light level and other properties will be appropriate to the dimension.  In the End, the ender dragon is present flying around and there are floating ender crystals, though the dragon cannot break or interact with blocks.  If the end portal is used in the End, the end credits will appear.
 * An end gateway portal will produce its purple beam each time the world is entered. It will not produce its yellow beam with players or entities, but it will if an ender pearl is used.  If using an ender pearl to use the gateway in the End, it teleports the player, but in keeping with debug mode world generation, there won't be any islands or a gateway portal back.

Gallery
Debug-Modus Tryb debugowania Режим отладки 调试模式