♦️Build Singleplayer & Multiplayer Logic

Use this one page guide to learn about Game Maker's logic systems and how they work together for single or multiplayer gameplay. Follow links as needed for more details in our documentation.

Game Maker's Logic Systems

GAME RULES

Rules are gameplay mechanics that can be triggered and completed repeatedly and use variables for all players or individual players.

Example: Points, Timers, Shops, and more

OBJECTIVES (QUESTS)

Quests are an individual player's progress in a singleplayer or multiplayer Experience's flow, which can be completed only one time.

Example: A quest to collect coins

OBJECT LOGIC

Behaviours & components are logic applied to voxel objects placed in the game world.

Example (image above):

Light, NFT Sensor, NFT Image Display, Play Sound & Trigger Volume

PLAYER SETTINGS

Player settings customize avatars, controls, basic features, and interactions in the world.

Example:

The player's avatar may be allowed to swim, may receive damage from certain blocks, etc.

Object Logic

[SP] & [MP] Behaviours and Components

A split between [SP] and [MP] logic was introduced with Game Maker 0.8.

This made it possible for players to experience some logic independently and other logic simultaneously with all other players. Synchronised logic includes position and state of objects, environment, global mechanics, etc.

An object may have one of the following logic setups:

No logic applied

Only [SP] logic "Client Only" - for each player to experience at different times Example: A player explores gameplay at their own pace and reads Quest dialogue when ready

Only [MP] logic "Networked" - for all players to experience at the same time Example: A door opening or a platform moving is synchronised for all players

In Singleplayer Experiences, [MP] logic works like [SP] logic. Gameplay design is more simple.

In Multiplayer Experiences, there are communication and bandwidth limitations to consider when designing gameplay.

Triggering Logic Across Systems

Logic can be a simple or complex chains of events, and it can be linear or branching with options.

There are many simple ways to send a message and trigger something to happen. Messages can also be directed more specifically using filters and tags.

Broadcast

Send a message on start of the Experience or when triggered, once or repeatedly.

Example:

Add a Message Broadcaster behaviour to a logic actor or object and set desired parameters.

Use a message broadcaster as a middle step if two logic elements will not send or receive messages as quickly, consistently, or specifically as you want.

Creating Experiences

👤 Singleplayer

One Layer of Logic

FULL DESIGN FLEXIBILITY

✅ [MP] and [SP] logic communicate with each other in singleplayer games.

✅ [MP] and [SP] logic communicate with an individual player's Objectives/quests.

✅ [MP] and [SP] logic communicate with Game Rules.

👥 Multiplayer

There are two layers of logic that do not communicate with each other, but must be designed to feel seamlessly integrated for players.

Toggle the Multiplayer Simulator at the top right in the Editor to test how the Experience will behave if published as singleplayer or multiplayer.

Two Layers of Logic

DESIGN RESTRICTIONS APPLY

❌ [MP] and [SP] logic DO NOT communicate with each other in multiplayer games.

❌ [MP] logic DOES NOT communicate with individual player Objectives/quests.

✅ [MP] and [SP] logic communicate with Game Rules.

[SP] is Client Only for individual players and [MP] is Synchronised for all players. Both can be used in single and multiplayer Experiences.

Use Objectives for individual player goals. Use Crowd Events for collective goals.

Behaviours and components without [SP] or [MP] in the name are not compatible with multiplayer Experiences yet. They will be ported in the future.

Why use [SP] logic in a multiplayer game?

[SP] logic is necessary in the game world to trigger quests, which track each player's individual progression in your game. Some logic may also only be available as [SP].

Performance

[MP] logic should be used minimally in multiplayer games to add more gameplay potential without reducing the fun. Start by using as much [SP] logic as possible and then add the [MP] layer. You can build the same player experience that performs more efficiently!

Consistency

1️⃣ Consistent Type

An object with [MP] logic may only have other [MP] logic added. An object with [SP] logic may only have other [SP] logic added.

2️⃣ Consistent Messages

An object with [MP] logic may only send messages to objects with [MP] logic. An object with [SP] logic may only send messages to objects with [SP] logic.

3️⃣ Consistent Hierarchy

An object with [MP] logic may only be a parent or child of an object with [MP] logic. An object with [SP] logic may only be a parent or child of an object with [SP] logic.

4️⃣ Consistent Spawn

An object with [MP] logic may only spawn an object or preset with [MP] logic. An object with [SP] logic may only spawn an object or preset with [SP] logic.

Variables (Game Rules)

Use Global (G) variables to track time, numbers, etc for all players.
Example: all players share the same timer value
Use Local (L) variables to track time, numbers, etc for each player.
Example: each player has a different timer value

To change a local variable (L), the message that triggers the Rule must be sent by a direct player interaction. It may be sent directly or the start of a chain of logic. This ensures the player source is sent to the rule to identify the correct player’s local variable to modify.

Global and local variables are unrelated to [SP] and [MP] differences. They can be used in a rule triggered by both types of logic.

Resources

PreviousRule Types NextQuality Guidelines

Last updated 6 months ago