Minecraft Wiki

Nearly all video games (including Minecraft) are driven by one big program loop. Just as every gear in a clock is synchronized with the pendulum, every task involved in advancing a game simulation is synchronized with the game loop. Appropriately, one cycle of the game loop is called a tick.

Game tick[]

A game tick is where Minecraft's game loop runs once. The game normally runs at a fixed rate of 20 ticks per second, so one tick happens every 0.05 seconds (50 milliseconds, or five hundredths of a second, or one twentieth of a second), making an in-game day last exactly 24000 ticks, or 20 minutes. However, if the computer is unable to keep up with this speed, there are fewer game ticks per second (TPS). As the vast majority of actions are timed based on tick count rather than on wall clock time, this means that many things take longer on a slower computer.

A statistic related to ticks per second (TPS) is milliseconds per tick (MSPT), the time a server actually uses to compute a tick. The TPS can be maintained at 20 only if the MSPT is no higher than 50. The following often contribute to server-side lag:

  • Hoppers constantly try to search for items above them. Cover with any item with an inventory slot or a composter, as this stops the checks for items. Alternatively, use water flow-based transport which is faster in bulk.
  • Redstone machinery. Redstone components, especially redstone dust cause excessive amounts of block updates and lag. Disabling redstone contraptions and clocks when not in use can help mitigate this.
  • Mob AI. Use torches to guide hostile mob spawning. Use more efficient farms for animals.

The MSPT value is displayed in the F3 debug screen as "ms ticks" in Java Edition. The frame time graph (Alt + F3) shows the TPS value. Both displays are available only as a multiplayer host or singleplayer since the stats come from the integrated server of your Minecraft game.

Game process[]

In Java Edition, in each game loop the following actions are processed in order:

Chunk tick[]


The extent of random tick, shown with the spread of grass on dirt. Notice how the grass follows chunk boundaries. The red and blue arrows in the center mark the +X and +Z directions. The player is in the (7,7) location in a chunk, slightly towards the north-west corner of the chunk, which means the centers of two chunks on the edge in the -X and -Z directions are brought within the 128-block radius, thereby allowing chunk tick processing. This is confirmed by the two one-chunk grass protrusions on the northern and western edges. (North is up)

As a part of a game tick, specific chunks are ticked on every game tick.

In Java Edition, chunks with loading type of entity ticking (see Chunk#Level and load type) and with horizontal distance between its center and a player (not in spectator mode) less than 128 blocks are ticked on every game tick. A few things should be noted here: first, the chunk should be loaded as an entity-ticking chunk. Second, if the chunk receives chunk tick, even if some blocks in the chunk are out of the 128-block radius, they can receive random tick as normal. Third, because 128 blocks is the horizontal distance, the player's position along the y-axis does not matter.

In Bedrock Edition, all chunks inside simulation distance (or specified in the /tickingarea command) are ticked on every game tick. Random ticking randomly occurs in blocks in ticking chunks, regardless of player position inside the chunk. The 128-block distance used in Java does not apply.

In both editions, the following things will happen when a chunk gets ticked:

  • Mobs naturally spawn.
  • During a thunderstorm, lightning may strike somewhere in the chunk (1100000 chance).
  • 116 chance that one column is chosen for weather checks on the topmost block:
  • A certain number of blocks within the chunk receive random block ticks, as described below.

Random tick[]

Chunks consist of one subchunk per 16 blocks of height, each one being a 16×16×16=4096 block cube. Sections are distributed vertically starting at the lowest y level. Every chunk tick, some blocks are chosen at random from each section in the chunk. The blocks at those positions are given a "random tick".

In Java Edition, the number of blocks chosen from each section is specified by /gamerule randomTickSpeed (defaults to 3), and one block can be chosen multiple times in one chunk tick. In Bedrock Edition, it also depends on randomTickSpeed (defaults to 1), but it specifies only relative speed instead of the exact number.

Most blocks ignore this tick, but some use it to do something:

Because random block ticks are granted randomly, there is no way to predict when a block can receive its next tick. In Java Edition, the median time between ticks is 47.30 seconds ( 946.03 game ticks). That is, there is a 50% chance for the interval to be equal or shorter than 47.30 seconds and a 50% chance for it to be equal or longer than 47.30. However, sometimes it is much longer or shorter: for example, there is a 1.38% chance for the interval to be less than one second and a 1.23% chance for the interval to be over five minutes. On average, blocks are updated every 68.27 seconds ( 1365.33 game ticks). For the math behind these numbers, see the Wikipedia entries for the geometric distribution.

Scheduled tick[]

Some blocks can request a tick sometime in the future. These "scheduled ticks" are used for things that have to happen in a predictable pattern—for instance, redstone repeaters schedule a tick to change state in Java Edition, water schedules a tick when it needs to move.

As a part of a game tick, each block position that has requested a scheduled block tick gets ticked on the specific game tick.

In Java Edition, there are two types of scheduled ticks: block ticks and fluid ticks. Block ticks are executed first based on priority, and then based on scheduling order. A lower value for priority results in earlier execution during the scheduled tick phase. If a redstone repeater is facing the back or side of another diode, its block tick will have a priority of -3. If a redstone repeater is depowering, it will have a priority of -2. Otherwise, the repeater will have a priority of -1. If a redstone comparator is facing the back or side of another diode, it will have a priority of -1. All other block ticks will have a priority of 0. Then, each block with a scheduled fluid tick will tick. Fluid ticks do not use priorities and are only ordered based on scheduling order.

In Java Edition, the maximum number of scheduled ticks per game tick is 65,536. In Bedrock Edition, the maximum number of scheduled ticks in a chunk per game tick is 100.

Redstone tick[]

The term redstone tick is a unit of time that describes a delay of two game ticks, creating a 110 of a second delay. Do note that redstone ticks are actually not a "real" thing that's handled by distinct game logic, but a term coined by the community to make communication about redstone easier, since most redstone components have delays of multiples of 2 game ticks. For example, a redstone repeater can have a delay of 2, 4, 6, or 8 game ticks, which could instead be described as having a delay of 1 to 4 redstone ticks.