GameMaker Visual Scripting Advanced Techniques

Keep your GML Visual actions readable as your GameMaker project grows, with clear names, one job per function, a folder habit, and notes that let future you follow the logic.

Your first graph was easy to read. A key press opened a door, and you could see the whole thing on one screen. Then you added enemies, pickups, a save system, and a boss. Now one object’s Step event scrolls forever, and you are not sure which block does what.

That is normal. Small visual scripts stay readable without help. Large ones need habits.

This guide assumes you already built a first working graph, like a key that opens a door. It covers how to organize GML Visual, which is what GameMaker’s manual calls its drag-and-drop action system, once your project has dozens of objects instead of three.

GameMaker updates its IDE often. If a menu or action name below does not match your version, check the current GameMaker manual.

Spot the warning signs

Before you reorganize, find out where it hurts. Open your three busiest objects and look for these signs:

• An event you have to scroll through more than once to read.
• The same chain of actions copied into several objects.
• Variables with names like temp, t2, or check.
• A block you are afraid to delete because you do not remember what depends on it.

Write down which objects show these signs. Fix those first. Leave the clean ones alone.

Name everything as if a stranger will read it

The stranger is you, three months from now. Good names do most of the work that comments would otherwise do.

Assets. GameMaker asset names can use letters, numbers, and underscores, and cannot start with a number. Pick a prefix for each type and stick to it. For example, obj_ for objects, spr_ for sprites, snd_ for sounds, and scr_ for scripts. The exact prefixes matter less than using the same ones everywhere.

Variables. Name a variable for what it means, not how you use it. door_is_locked tells you more than flag. hp_max and hp_current are clearer than hp and hp2.

Functions. Start function names with a verb. door_open, player_take_damage, and pickup_collect all read like instructions. If you cannot name a function with a short verb phrase, it probably does too much.

Give each job one home

The biggest change on a larger project is moving repeated action chains out of object events and into functions.

GameMaker’s manual describes a Declare A New Function action. You can add it to a script asset, give the function a name and arguments, and drag the actions it should run under it. Elsewhere, you use the Function Call action to run it. Functions declared in a script this way are global, so any object can call them.

Here is how to refactor one repeated chain:

1. Find a sequence that appears in more than one object, like reducing health, playing a hurt sound, and flashing the sprite.
2. Create a script asset named for the area, such as scr_combat.
3. Add a Declare A New Function action. Name it player_take_damage and give it an argument for the amount.
4. Move the actions into the function and replace hard-coded numbers with the argument.
5. In each object that had the chain, delete it and add a single Function Call to player_take_damage.
6. Run the game and test every place that used the old chain.

Now there is one place to change how damage works. Your events get shorter, and each one reads like a list of steps rather than a wall of detail.

One script can hold several related functions. Keep combat functions together, door functions together, and save functions together.

Keep events short and readable

Aim for events you can read without scrolling far. When an event grows, ask which part is a separate job and move it into a function.

A Step event for an enemy might end up as just four calls: enemy_update_state, enemy_move, enemy_check_attack, enemy_update_animation. Each call hides a block of actions you can open when you need it. You can read the enemy’s whole behavior at a glance.

The same idea applies to conditions. If a single If block checks five things at once, split it. Give the result a name, such as can_attack, and set that variable before the check. Then the If reads like a sentence.

Leave notes where the logic is not obvious

The GameMaker manual notes that you can add comments to GML Visual actions, leaving a note beside a block to explain it. Use these for the why, not the what. The action already shows what it does.

Good comments sound like:

• “Wait one frame so the door sprite finishes before collision turns off.”
• “Boss ignores knockback during phase two.”

The manual also describes naming an event by placing an Execute Code action at the very top with a short description line. That label helps when you skim an object’s event list. Check the current manual for the exact format your version expects.

For functions, the manual recommends a short comment that describes what the function does and what each argument means. Do it when you create the function, while you still remember.

Build a folder habit

GameMaker’s Asset Browser lets you create groups, which act as folders, and drag assets into them. You can organize by asset type or by game area. Both work. Mixing them randomly does not.

For a mid-size solo project, a hybrid often stays clear:

• A Core group for things used everywhere, like your game controller, combat scripts, and save scripts.
• One group per area or feature, like Forest, Caves, or Shop, holding that area’s objects, sprites, and sounds.
• A Testing group for debug rooms and throwaway objects, so they never mix with real content.

The Asset Browser also supports tags, which you can use to filter the list. Tag work-in-progress assets so you can find unfinished pieces quickly.

Whatever you choose, write the rule down in a short text note inside the project. When you add an asset, put it where the rule says right away. Cleaning up later never happens.

Use parents for shared behavior

If five enemy types share the same movement and damage logic, put that logic in one parent object and let the enemies inherit it. Each child only needs the events that make it different.

That keeps shared behavior in one place, much like functions do. When you change how enemies take damage, you change it once. Check the manual for how your version lets a child run its parent’s event as well as its own.

Debug without breaking everything

On a larger project, you will often need to switch off part of an event to find a bug. GameMaker lets you disable selected actions in GML Visual rather than delete them. Use that to narrow down a problem, then re-enable or remove the block once you know.

The manual also describes a live preview that shows the code your actions generate. Opening it can help you see what a confusing chain does under the hood. Converting an event to code is a one-way change, so preview first and only convert on purpose.

A weekly tidy-up

Set aside a short session each week:

1. Open the object you edited most.
2. Move any repeated chain into a function.
3. Rename any vague variable.
4. Add one comment where you hesitated.
5. Move stray assets into the right group.

Small, regular cleanups keep a project readable. A huge cleanup at the end rarely gets finished.

Test the stranger rule

Once a month, pick an object you have not touched in weeks. Open it and try to explain each event out loud in one sentence. If you cannot, that event needs a better name, a function, or a comment.

Your project should read like a set of short, labeled instructions. When it does, adding the next feature feels like adding to a system instead of digging through a pile.