Roblox UI Design — Layout, Color, and Sizing Guide

1. UDim2 — the foundation of Roblox UI sizing

Every Roblox GUI element uses UDim2 for Position and Size. A UDim2 has two axes, each with a Scale component (0–1, fraction of parent) and an Offset component (pixels). Understanding when to use each is the single most important Roblox UI design skill.

Use Scale for anything that should grow or shrink with the parent: panel widths, row heights, padding ratios. Use Offset for things that must stay a fixed pixel size: icon dimensions, corner radius, small gaps.

A common pattern: Size = UDim2.fromScale(0.8, 0.6) for the main panel, then Size = UDim2.fromOffset(32, 32) for icons inside it. This keeps the panel proportional but the icon crisp.

2. AnchorPoint and alignment

AnchorPoint decides which corner of an element its Position refers to. The default is (0, 0) — top-left. Setting it to (0.5, 0.5) centers the element on its Position coordinate.

For centered panels, always set AnchorPoint to (0.5, 0.5) and Position to UDim2.fromScale(0.5, 0.5). This centers the panel regardless of screen size.

For corner HUDs, use AnchorPoint (0, 0) for top-left, (1, 0) for top-right, (0, 1) for bottom-left, and (1, 1) for bottom-right. Then Position with Scale values like (0.02, 0) or (0.98, 0) to keep a small margin from the edge.

3. Color palettes that work in Roblox

Roblox games run on a huge range of screens — bright laptop monitors, dim phone screens, and everything in between. Your palette needs enough contrast to be readable everywhere.

A safe starting palette: dark background (Color3.fromRGB(18, 18, 24)), light text (Color3.fromRGB(230, 230, 240)), and one accent color (Color3.fromRGB(0, 162, 255) for interactive elements). This gives you a 12:1+ contrast ratio on the text.

Avoid pure white (#FFFFFF) for large background areas — it is harsh on eyes in a dark game. Use off-white (#E6E6F0) or a very light blue-gray instead.

For status colors: green (#22C55E) for success, red (#EF4444) for errors, yellow (#EAB308) for warnings. Keep them consistent across the entire UI.

4. Font pairing and text hierarchy

Roblox offers several built-in fonts. For a clean modern look: GothamBold or GothamBlack for headings, GothamMedium for body text, and Code for technical labels.

Establish a clear text hierarchy: H1 (titles) at 28–36px, H2 (section headers) at 20–24px, body text at 14–16px, and captions at 11–12px. Stick to these sizes across the entire GUI.

Line height matters more than you think. In Roblox, TextLabel.TextWrapped = true with a generous frame height gives you natural line spacing. Avoid cramming text into tight frames.

For dark backgrounds, use TextColor3 with high brightness (200+). For light backgrounds, use low brightness (30–60). Never use mid-gray text — it is unreadable on both.

5. Spacing with UIListLayout and UIPadding

UIListLayout is the Roblox equivalent of CSS flexbox. Drop it into a Frame and every child stacks automatically — vertically or horizontally, with configurable padding and alignment.

Use UIPadding on the parent Frame to create consistent margins. A good rule: 16px outer padding, 8–12px between items. This matches modern web design conventions and feels natural to players.

For grids (shops, inventories), use UIGridLayout with CellSize in Scale for responsive columns. UDim2.fromScale(0.3, 0) with a UIAspectRatioConstraint gives you square cells that resize with the parent.

For button rows, use UIListLayout with FillDirection = Horizontal and a small Padding value. Each button gets a fixed Offset width so they stay tap-friendly on mobile.

6. Responsive design for mobile and desktop

Roblox players use phones, tablets, desktops, and consoles — sometimes in the same server. Your GUI must work on all of them.

The core principle: use Scale-based sizing for containers and layouts, then add UITextSizeConstraint and UIAspectRatioConstraint for fine control over text and aspect ratios.

For mobile: minimum tap target is 44x44 pixels (Apple HIG standard). Keep buttons at least this size. Use UIListLayout spacing of 8px minimum between tappable elements.

For desktop: you can afford denser layouts with smaller text. But keep the same Scale-based structure so the layout reflows naturally.

Test with the Roblox Studio emulator at 360x640 (phone), 768x1024 (tablet), and 1920x1080 (desktop). If it looks right at all three, it will work everywhere.

7. Visual hierarchy and information architecture

Every screen should have one clear focal point — the thing the player should look at first. Use size, color, and position to draw the eye there.

Group related elements visually. A Frame with a slightly different BackgroundColor3 and a UICorner creates a card that says 'these items belong together.'

Use consistent spacing between groups (16–24px) and tighter spacing within groups (8–12px). This creates a visual rhythm that players intuitively understand.

Limit the number of visible actions per screen. A main menu needs 3–5 buttons, not 15. If you need more, use sub-screens or tabs.

8. Export and iterate with Roblox GUI Maker

Design decisions are hard to undo once you have written 500 lines of Luau. Roblox GUI Maker lets you preview layouts visually, test responsive behavior, and export clean code — so you can iterate on design before committing to scripts.

Start from a template that matches your screen type (main menu, shop, inventory, HUD), adjust the properties in the visual editor, preview on multiple device sizes, and export when the layout feels right.

The exported Luau uses real Roblox property names (BackgroundColor3, UDim2, UIListLayout) so you learn the API while designing. Every property you tweak in the editor maps directly to a Luau line you can read and modify.