Broadcast

Broadcast events are fire-and-forget server-to-client messages sent by broadcast:Emit() over an UnreliableRemoteEvent — individual events may be dropped, but bandwidth cost is minimal.

How broadcast events arrive

On the server you call broadcast:Emit(event, data). On the client you subscribe with the same listener:On(event, fn) used for push events. Listener automatically routes broadcast payloads alongside push payloads — you write one handler for both.

copy-- SERVER (Script)
local broadcast = RoExpress("Broadcast")

-- emit every heartbeat — drops are acceptable
game:GetService("RunService").Heartbeat:Connect(function()
    for _, player in game.Players:GetPlayers() do
        broadcast:Emit("position.hint", {
            player = player.Name,
            pos    = player.Character and
                     player.Character:FindFirstChild("HumanoidRootPart") and
                     player.Character.HumanoidRootPart.Position
        })
    end
end)

-- CLIENT (LocalScript)
local listener = RoExpress("Listener")

listener:On("position.hint", function(data)
    Minimap:UpdateDot(data.player, data.pos)
end)

Reliability

Broadcast uses Roblox's UnreliableRemoteEvent. Events are not retransmitted on packet loss — any given emission may never arrive at the client. This is intentional: for high-frequency data it is cheaper to accept occasional drops than to guarantee every packet.

Broadcast vs Push

Hit FX example

Visual effects are a perfect fit for broadcast — a missed frame is invisible to the player, and flooding the reliable channel for every shot is wasteful.

copy-- SERVER fires a hit effect for everyone nearby
broadcast:Emit("hit.fx", { pos = hitPos, weapon = "rifle" })

-- CLIENT plays it
listener:On("hit.fx", function(data)
    FX:PlayImpact(data.pos, data.weapon)
end)

See also

← Listener  ·  Subscribe | On, Once, Off reference  ·  Server Push | reliable channel comparison  ·  Broadcast module | server-side emit API  ·  Gun Example | hit FX via broadcast