A GUI, which stands for Graphical User Interface, is used to display information about the game to the player. GUIs can be used to show the player what their character's level, health, and gold are, and also to create in-game buttons for menus and inventory systems. In the image below, the game developers of Hexaria use GUIs to both show information about the player and to create an in-game menu.
The most common type of GUI is a screen GUI which behaves like a 2D place to put stickers on the player's screen. When the player moves the camera or explores the game world, a screen GUI stays in the same place (on the screen).
When you make a new Roblox game, this screen GUI space doesn't exist — it's your job to add it. The easiest way is to add it to the StarterGui service so that it gets copied to a player's local game session when they join the game.
Currently the new screen GUI is empty — it's just a blank canvas that spans the entire width and height of the player's screen.
All sorts of things can be added to the screen GUI. Let's start with a basic text label.
We have a text label on the screen, but a white box with the word Label isn't very useful. Let's customize it to look like a "version number" GUI, a display element usually found on the menu/intro screen which shows the current version of the game.
Great! The GUI object looks much better now! If you want to get even more creative, try changing properties like TextColor3, BackgroundColor3, BackgroundTransparency, and others.
Now that we have a basic text object on the screen, let's move it to a new position. Every 2D object in Roblox has a Position property which determines where it will be drawn in relation to its parent object. This position is set by X and Y coordinates where X is the horizontal position and Y is the vertical position.
When first created, all 2D objects start with an X and Y position of 0 which is the top-left corner of the screen, but what if you want to move it? Let's look at the Position property of the text label and learn how!
The Scale property represents a percentage of the parent object's width or height. Remember that the screen GUI "canvas" spans the full width and height of the 3D game view — that means the Scale property can be used to position an object directly at the center of the view, against the left or right edge, or anywhere between based on a percentage of the screen's full width or height.
Although Scale indicates a percentage, the range of values that you enter should usually be between 0 and 1, where 0 equals 0% and 1 equals 100%. For example:
Scale = 0.1
10% of full width or height
Scale = 0.5
50% of full width or height
Scale = 0.95
95% of full width or height
Now let's move the text label to the horizontal center of the screen. Simply enter 0.5 for the Scale value of X and press the Enter/Return key to confirm.
The text label should now be positioned more toward the center of the game view.
Remember that your game will be played on screens which vary in width versus height. For example, a phone screen may be slightly wider (and less tall) than a PC or console screen. Scale is the best choice for positioning an object in the center of the view because it will remain in the center on many different screens.
The second property in each set is called Offset. Instead of moving the element by a percentage of the parent's size, it moves it by a specific number of pixels. This can be useful if you want to place a GUI element slightly inside any edge of the game view.
Let's move the text label just slightly inside the top edge of the screen. Enter 50 for the Offset value of Y and press the Enter/Return key to confirm.
Now the text label should be inset just slightly from the top edge of the screen.
Offset is the best choice for positioning an object near any edge of the view. Using this option will make sure it remains in the same basic screen position on PC, console, tablet, and phone.
If you look carefully at the current position of the GUI object, you'll notice that it's not perfectly centered left-to-right, even though we set Position → X → Scale to 0.5 (50%).
This is because of the object's default anchor point. An anchor point is a specific point on the object to align with the screen position you set. Imagine the anchor point like a pin stuck through a piece of paper — the pin can be put through any place on the paper, and Roblox will align that pin point with the Position value(s) you set for the object.
In the game editor window, the anchor point is shown by the small square outline on the object (when it's selected). When you create a new GUI object, the anchor point is set to the top-left corner — this is why that exact point on the object is aligned to the X and Y position values set earlier.
The anchor point is based on an X and Y value which is a percentage of the object's size: 0 equals 0% and 1 equals 100%.
You can use this concept to center the GUI object in the exact middle of the screen.
The text label should now be positioned exactly in the center of the game view.
As you can see, the Position and AnchorPoint properties let us put elements anywhere we need to within a screen GUI. We can also change the size of any element using its Size properties.
For setting the size of a GUI object, the Scale property works the same as it does for positioning, representing a percentage of the parent object's width or height. If you set Size → X → Scale to 0.5 (50%), the object will be exactly half of the screen width.
Let's experiment and see what happens!
The text label should now take up exactly 75% of the screen width.
As you noticed above, Size also has a property called Offset. For sizing, Offset is useful if you want to create buttons, labels, or other objects which stay the same number of pixels (width or height) no matter what screen they're being viewed on.
To increase the height of the text label, simply enter 150 for the Offset value of Y and press the Enter/Return key to confirm.
Now the text label should be quite a bit taller than before!
Some GUI layouts are only possible with creative combinations of Scale and Offset values. You can explore this by making the TextLabel object fill the entire screen with a small margin of 20 pixels around all four edges.
Great! That covers the basics of GUIs, how to create a screen GUI canvas for all players that enter your game, and how to position and resize GUI objects on the screen.