Learning Roblox Scripting – Struggling with Client-Server

[minor ember]

Hey, I’m learning Roblox scripting and also relearning Lua from scratch. I have experience with JavaScript, C#, C++, and Python, but I never fully understood how the client-server system works (LocalScripts, ServerScripts, Remote Events, etc.). This has always been a roadblock for me.

Can someone clearly explain how client-server communication works and when to use each type of script? Also, how did you approach learning scripting when you first started? Any good resources you’d recommend?

[solar remnant]

client server cant change server sided value or anything on server.

so u need to use remote events to do that

i learn scripting my watching videos

[minor ember]

can you give me some channels to watch?

[solar remnant]

TheDevKing?

[minor ember]

alright

thank you

[agile sierra]

its easy bro like client is what the players can do or the client do that the servers cant like clicking a button.

guis, etc.

but you can communicate to the server by using remote events

like if you click the button on the client you will tell the server to do something about it

also there is something like um filter enabled thingy

[minor ember]

thanks that makes sense so anything the player directly interacts with (like ui , buttons,etc.) runs on the client if i need to make changes that effect the whole game i communicate with the server using remote events got it

[agile sierra]

like if you change something on the client like changing a part on the client side the players will not see it the changing position of a part simply because it doesnt replicated on the server.

[agile sierra]

yes

exactly

if you want to make the other player see the changes in your client side then you will need to communicate with servers

[minor ember]

also i can optimize the game with those right

[subtle meadow]

the server is the server. pretty self-explanatory. clients are each person's computer/device/phone/etc. they don't share information unless you tell it to share information (remote events, etc). roblox has a lot of conveniences to make this easier, like creating a part in workspace on the server automatically shares it with all clients who are near it

whats important to realize is that the server doesn't see the same world as each client does. like you can create a part on a client and only that client will see the part.

[minor ember]

like if i make the particles and destruction physics run on the client side it wont cause lag for other players

[sage vine]

** You are now Level 1! **

[subtle meadow]

everything that cross the client/server boundary has a networking cost to it. 1000 moving parts is very expensive.

[minor ember]

got it

thank you for your help

[subtle meadow]

if you do the moving parts on the client, yeah it's cheaper, but you are limited by the client's device instead of network capacity

like a phone aint gonna handle a massive building exploding into 10k tiny pieces

[agile sierra]

to optimize your game i can give little tip if you are using tween service then you should it on client side rather than server side 🙂

tween service can be use both server and client but this is not useful for uhm server because y'know it also leads memory leaking

[subtle meadow]

nah memory leak aint the issue. it adds networking cost

networking is usually the largest bottleneck

[agile sierra]

oh okay i dont know what the networking cost tho? maybe i am lacking something

[subtle meadow]

memory leaks only happen if you dont clean up old data

[agile sierra]

but yeah this is just a little tip to avoid lag sometimes

[subtle meadow]

i.e if you create a part in workspace, and an objectvalue with its value set to that part, and then you delete the part, the objectvalue will still have a valid reference to the part, and the part stays in memory until the objectvalue is destroyed

that's a memory leak if you do something like that and never clean it up

[agile sierra]

yeah. but i have a question how do you clean up the old data that has been destroyed but its still reference in the memory?

like if a player joins does it mean it adds it to the memory?

[subtle meadow]

a pretty common one is collecting players into a table on playeradded. if you don't destroy references to the player like on playerremove, that player's old object stays in memory

"destroying a reference" usually just means setting stuff to nil

[agile sierra]

ah okay so whenever player joins i will make a table which is "playerTable" and add them to this table. and whenever they leave i will just set the player into nil value in the table?

[subtle meadow]

like playertable[plr.userid]=plr

same for playertable[plr]=plr.userid

if you don't set those to nil, the player stays alive

[agile sierra]

game.Players.PlayerAdded:Connect(function(plr)
    plrTable[plr.UserId] = plr
end)

game.Players.PlayerRemoving:Connect(function(plr)
    plrTable[plr.UserId] = nil
end)```

how about the character?

like if they died multiple times?

[subtle meadow]

yep same thing if you keep references to old characters they stay alive

[agile sierra]

ok so i will make another table for character? and make it nil?

whenever the char died

?

[subtle meadow]

what hahaha where did that come from

if you never store the player in a table to start with you dont have to care