DataStores — saving between visits

Right now, everything you've built dies when the game stops. Close the test and your coins are gone. Real games remember you. That memory lives in a DataStore — and this lesson is where your game gets a brain that survives restart.

#The shape of saving

Saving is always the same dance:

1. Get the store. One shared storage area, like a filing cabinet.
2. Load — on join, pull out that player's file.
3. Save — when they leave (or periodically), write it back.

local DataStoreService = game:GetService("DataStoreService")
local coinsStore = DataStoreService:GetDataStore("Coins")

GetDataStore("Coins") gives you a filing cabinet named "Coins". Inside it, each key is a player. So "Sam's file" = key "Sam", value 50.

#Save and load

Two methods do almost all the work:

coinsStore:SetAsync(player.UserId, coins)   -- write a value
local coins = coinsStore:GetAsync(player.UserId)  -- read it back

• SetAsync(key, value) — "set asynchronously": write the value to the store. Roblox does the slow network work in the background so your game doesn't freeze.
• GetAsync(key) — returns the saved value, or nil if there's no save yet.

Notice the key is player.UserId — the permanent number from last lesson. The key is who; the value is what.

#The full save loop

Load on join, save on leave. That's the entire shape of persistence:

local DataStoreService = game:GetService("DataStoreService")
local coinsStore = DataStoreService:GetDataStore("Coins")
local Players = game:GetService("Players")

Players.PlayerAdded:Connect(function(player)
    local coins = coinsStore:GetAsync(player.UserId) or 0
    -- ...build leaderstats with coins...
end)

Players.PlayerRemoving:Connect(function(player)
    local coins = player.leaderstats.Coins.Value
    coinsStore:SetAsync(player.UserId, coins)
end)

Every game with player progress — cash, levels, pets — is this pattern with different values.

Players.PlayerRemoving:Connect(function(player)
-- your save line
end)

#Common mistakes

• Testing saves in Studio and thinking it's broken. Saves don't persist in Studio — the store only fully works in a published place.
• Saving on PlayerAdded. That saves the starter value before they've earned anything. Save on leave.
• Using the key as the saved value. The key is UserId, the value is coins. Getting them backwards stores a number with a number for a key.
• Forgetting the nil check. New player, no save → GetAsync gives nil. Default it with or 0.

Next: loading a player's data in detail — and handling brand-new players.