Lag

An example of fire lagging in a popular game called "Welcome to Roblox Building" by ROBLOX (user).

Lag is an occurrence in many places in which in-game movement and actions become slowed, frozen, or out-of-sync due to slow network latency. "Lag" can also refer to a low framerate or an unresponsive process. Lag can be very devastating for some players, and there are varying degrees, from slight jerkiness (mild lag) to total process freezing (extreme lag). Lag can occur from various things such as too many projectiles firing from a weapon or too many blocks (especially unanchored ones) present in a server.

Lag can be rather annoying to many players whenever it happens to their computers and can occur in many place servers.

There are a variety of lag types in ROBLOX, in 3 main categories:

• Client lag, experienced by one user, due to their bad internet connection

• Server lag, experienced by all players, due to the server's lack of processing power (too many things happening at once)

• Low FPS, experienced by one user, due to their device's lack of processing power (too many parts, too much detail)

Types of Lag

• Ping (Latency) - The main cause of delay. Players who have very slow internet (such as dial-up) will get high ping which will result in a delay with almost all actions. More can be seen here. However, this can be fixed by server hopping. Ping is usually calculated in milliseconds (ms), and the higher ms your ping is, the more laggier you are. The latency when a user is lagging is usually 1000< ms.
• Block Lag - This usually occurs when there are approximately 10,000 blocks or more present in a server. It hits hardest when you look at all of them, or if the majority of them are un-anchored.
• Decal Lag - Thousands of decals will cause lag when the player looks at all of them at the same time, similar to bricks.

• Entry Lag - One of the most common types of lag occurs just as the player enters a server, with the lag usually disappearing after some time. If this particular player has a large amount of saved data (see here), the lag experienced is more substantial. Multiple players joining simultaneously is another factor affecting this lag.
• Internet Lag - This type of lag occurs when the player has a slow internet connection speed.
• Server Lag - This is when the player's computer and/or internet is functioning properly, but the server is lagging severely, these actions that occur on the server are delayed and every other player present appears to freeze up, except for the player itself (this is because the client itself isn't lagging). This is less common, and the only way to stop it is for the player to quit the game, and join a different server.
• Excessive Lag - This is a rare kind of lag and could occur when the computer and internet is slow/weak, the server is lagging at the same time and other websites and applications are competing for CPU and internet usage. Lost connections, hardware failures and game crashes are most likely to occur during this, due to the combined risks.
• Tool Lag - This lag occurs when a player has too many tools. This especially is more likely to occur when a player has too many gears in a gear game. It will only happen if the player joins, resets, or gets KO'ed. It is generally due to multiple scripts running at once.
• Other Player Lag - This lag affects character entities belonging to other players who experience lag of any kind, which causes them to suddenly stop, then teleport to nearby areas every few seconds. You, everyone else and the server are not affected, apart from resulting possible vehicle collisions.
• CPU-Hungry External Programs - Certain websites and external apps can cause ROBLOX to lag by hogging up CPU usage, eventually leading to freezes and possible crashes. It can be avoided by closing CPU-hungry websites and external programs, installing a faster CPU, or getting a computer specifically designed for gaming.
• Chat Lag - This type of lag happens when too many people are typing/spamming at once(such as spamming hashtags [#]), or if a bot is spamming repeatedly. 
• Input lag - This is a type of lag common in games with custom movement systems, where a movement button has a delay after being pressed.

Trivia

This section is a trivia section. Please relocate any relevant information into other sections of the article.

• Some players deliberately cause lag via spamming instances of any kind to troll, kill or crash others. This is called “lag switching”. This can lead to a ban.
• Lag can also be detrimental for developers as it drives users (and therefore profit) away from the affected game.
• Lag is one of the things that are complained about by many players on ROBLOX.
• Lag causes higher difficulty in obbies, vehicle-related games, fighting games, and survival games.
• Lag often causes players to be unable to escape from players trying to kill them, because as some users would usually walk over to the player to kill him/her, they would be unable to move as they come closer to them.
• Contrary to popular belief, meshes do not create lag. However, decals do create lag, as proven in this place. However meshes use more disc space than normal bricks.
• Back in 2007 or 2008, when the server was lagging, actions that occur on the server were delayed and every other player present appears to freeze including the player character him/herself.
• Lag is not just found on Roblox, it can be found on many other games including both online & offline games and even games on video game consoles.
• Scripts can cause lag if they have numerous loops in them and/or are infected scripts, they can also cause lag if they are doing intensive work all at once.