Use the Interpreter in an event
Pokémon Studio v3.0 will move away from RPG Maker. When that release ships, this RPG Maker XP section will be archived: the pages will remain available as reference but will no longer be updated.
In RMXP, when creating an event, you have access to standard commands: show a message, give an item, teleport the player. But these commands are limited. PSDK provides dozens of ready-to-use methods that can be called directly from an event's Script command. This guide explains where these methods come from, how to use them, and most importantly how to find them.
What is the Interpreter?
When an event runs on the map, an object called the Interpreter processes each command one by one. This object is created when the map loads and lives as long as the map is active. Each RMXP command (show a message, move an event, play a sound) corresponds to a method on this object.
What makes the Interpreter powerful in PSDK is that the engine extends it with many additional methods. Where base RMXP can only do simple things, PSDK adds methods to manage Pokémon, start battles, open menus, move the camera, and much more.
The Script command
The RMXP Script command lets you write Ruby code that runs inside the Interpreter. This means you can call all its methods directly, without any prefix:
message("Hello!")
add_pokemon(:pikachu, 10)
emotion(:exclamation)
These three lines call three Interpreter methods. You don't need to write self.message(...) or reference any object — the code already runs in the right context.
You can also write any valid Ruby expression. You have access to global variables ($game_variables, $game_switches, $actors, $bag...) and all of the engine's code.
Access shortcuts
The Interpreter exposes shortcuts to quickly access the game's global objects:
| Shortcut | Returns | Full name |
|---|---|---|
gv | Game variables | $game_variables |
gs | Game switches | $game_switches |
gt | Game temp | $game_temp |
gm | Game map | $game_map |
gp | Game player | $game_player |
ge(id) | A map event | $game_map.events[id] |
party | Game state | PFM.game_state |
For example:
# Set variable 10 to 42
gv[10] = 42
# Enable switch 5
gs[5] = true
# Get the player's speed
gp.move_speed
# Get event 3 on the current map
ge(3)
These shortcuts are simply methods that return the corresponding global objects. They are used to write more concise code in the Script command.
Script conditions
In RMXP, the Conditional Branch command has a Script tab. The code written there also runs inside the Interpreter, but it must return a value: if it's truthy (neither false nor nil), the condition is true.
# Does the player have a Pikachu?
$actors.any? { |pokemon| pokemon.db_symbol == :pikachu }
# Is variable 10 greater than 50?
gv[10] >= 50
# Is the party full?
$actors.size == 6
# Does the player have a Master Ball?
$bag.contain_item?(:master_ball)
Any Ruby expression works. This is where the shortcuts (gv, gs, etc.) become very useful to keep code short.
Where to find available methods
This is the key question: how to know which methods exist and what parameters they accept?
The online documentation
The PSDK YARD documentation is available at:
https://psdk.pokemonworkshop.fr/yard/Interpreter.html
The Interpreter class is documented there with all its methods, their parameters, and their types. This is the most accessible reference — it requires no installation.
The source files
For those who prefer reading the code directly, all Interpreter methods are defined in pokemonsdk/scripts/2 PSDK Event Interpreter/. Each file corresponds to a theme:
| File | Theme |
|---|---|
100 Interpreter_Environnement.rb | Player detection, event deletion |
105 Interpreter_Camera.rb | Camera movement |
110 Interpreter_Pokemon.rb | Add, remove, modify Pokémon |
120 Interpreter_Shortcut.rb | Shortcuts, emotions, menus, pathfinding |
121 Interpreter_add_item.rb | Item management |
125 Interpreter_Fiber.rb | Messages and choices |
130 Interpreter_Sequences.rb | Battle sequences, trades |
140 Interpreter_Player.rb | Player profile management |
150 Interpreter_Time.rb | Timed events |
160 Interpreter_Overlay.rb | Map overlays |
165 Interpreter_Message_Font.rb | Message font |
These files are part of PSDK's internal code. To access them, you need to follow guide 003 How to set up the development environment which explains how to retrieve the engine's source code. Without this step, the pokemonsdk/ folder is not visible in the project.
Each method in these files is documented with YARD comments that describe the parameters and their types. By reading a file, you can quickly discover everything available for a given theme.
Adding your own methods
The Interpreter is a Ruby class like any other. You can reopen it from your own scripts to add methods. All scripts placed in the scripts/ folder at the root of the project are loaded by PSDK after the engine's code.
For example, if you want a reusable method to heal the entire party:
# my-project/scripts/001 Interpreter.rb
class Interpreter
# Heal all Pokemon in the party
def heal_all_pokemon
$actors.each do |pokemon|
pokemon.hp = pokemon.max_hp
pokemon.status = 0
pokemon.skills_set.each { |skill| skill.pp = skill.ppmax if skill }
end
end
end
Once this file is in place, the method is available in all events in the game:
# In a Script command
heal_all_pokemon
message("Your Pokemon have been fully healed!")
This is the same principle as the monkey-patching described in guide 001 What is monkey-patching and how to apply it in PSDK: you reopen the class, add a method, and it becomes accessible everywhere. The difference is that here you're not modifying an existing method — you're creating a new one.
This is useful for several reasons:
- Factoring out code: instead of copy-pasting the same Script block in multiple events, you write it once in a method and call it by name.
- Simplifying events: RMXP's event editor is not designed to handle complex logic. Nested conditional branches, lengthy events and mixing RMXP commands with Script blocks quickly become unreadable. By moving that logic into a Ruby method, the event is reduced to a simple call, and the code is easier to read, test and modify.
Conclusion
- The Interpreter is the object that executes event commands. PSDK extends it with dozens of additional methods.
- The Script command and the Script tab in conditional branches execute Ruby directly inside the Interpreter.
- The shortcuts (
gv,gs,gp,ge,party) simplify access to game data. - To discover available methods: check the YARD documentation or read the source files after following guide 003.