Use when building, animating, or debugging Roblox GUI elements including HUDs, menus, world-space UI, and player labels. Triggers on: ScreenGui setup, SurfaceGui or BillboardGui placement, UDim2 sizing questions, TweenService UI animations, responsive scaling, LocalScript GUI logic, ResetOnSpawn iss

Roblox GUI Reference GUI Container Types Container Parent Use Case ScreenGui PlayerGui HUDs, menus, overlays — always faces screen SurfaceGui BasePart World space UI on a part surface (signs, screens) BillboardGui BasePart or Model Floats above a part in 3D space (name tags, health bars) ScreenGui SurfaceGui BillboardGui UDim2 Sizing and Positioning UDim2.new(xScale, xOffset, yScale, yOffset) — scale is 0–1 relative to parent, offset is pixels. AnchorPoint shifts the element's pivot (0–1 on each axis): Responsive Design Prefer scale over offset so UI adapts to all screen sizes. TweenService Animations LocalScript Placement Location Notes StarterGui Cloned into PlayerGui on join; use ResetOnSpawn = false to persist StarterPlayerScripts Runs once, not reset on respawn; good for persistent managers StarterCharacterScripts Re runs each spawn; suited for character dependent UI ResetOnSpawn Common Patterns Quick Reference Pattern Key Setup Full screen overlay Size = UDim2.fromScale(1,1) , Position = UDim2.fromScale(0,0) Bottom center HUD bar AnchorPoint = (0.5,1) , Position = UDim2.new(0.5,0,1, 10) Padded list UIPadding + UIListLayout inside a Frame Scrollable list ScrollingFrame + UIListLayout ; set CanvasSize from UIListLayout.AbsoluteContentSize Rounded corners UICorner with CornerRadius = UDim.new(0, 8) Scaled text TextScaled = true on TextLabel/TextButton so font grows with container Dynamic frame height AutomaticSize = Enum.AutomaticSize.Y so frame expands to fit children Health bar Nested frames: outer = background, inner tweened by Size.X.Scale Name tag BillboardGui on Head, StudsOffset = Vector3.new(0, 2.5, 0) Common Mistakes Mistake Fix GUI disappears on respawn Set ResetOnSpawn = false or use StarterPlayerScripts UI looks wrong on mobile Use UDim2.fromScale + UIAspectRatioConstraint Script can't find PlayerGui Use player:WaitForChild("PlayerGui") Tween doesn't run Ensure the property is tweenable; Text is not, Position and Size are BillboardGui visible through walls Verify AlwaysOnTop = false AbsoluteSize is zero on first frame Read it inside task.defer or after first render step Clicks pass through overlapping frames Add a transparent input blocking Frame or set Modal = true SurfaceGui flickers Set LightInfluence = 0 ; ensure part isn't too thin Text tiny on mobile Set TextScaled = true — fixed TextSize doesn't adapt to screen size UI hard to test on mobile Use Studio's Device Emulator (Test tab → Device) to preview layouts

roblox-gui