# Reserved Names

Ren'Py reserves filenames that are do not begin with a letter or number, and filenames that begin with "00". Very specifically, filenames that start with "00" and "_" are used by Ren'Py internally.

Ren'Py reserves all names beginning with a single underscore (_). Do not use names beginning with an underscore, as that may cause your game to break in future versions of Ren'Py.

The following is a list of names that are used by Python. Re-using these names can lead to obscure problems.

- ArithmeticError

- AssertionError

- AttributeError

- BaseException

- BaseExceptionGroup

- BlockingIOError

- BrokenPipeError

- BufferError

- BytesWarning

- ChildProcessError

- ConnectionAbortedError

- ConnectionError

- ConnectionRefusedError

- ConnectionResetError

- DeprecationWarning

- EOFError

- Ellipsis

- EncodingWarning

- EnvironmentError

- Exception

- ExceptionGroup

- False

- FileExistsError

- FileNotFoundError

- FloatingPointError

- FutureWarning

- GeneratorExit

- IOError

- ImportError

- ImportWarning

- IndentationError

- IndexError

- InterruptedError

- IsADirectoryError

- KeyError

- KeyboardInterrupt

- LookupError

- MemoryError

- ModuleNotFoundError

- NameError

- None

- NoneType

- NotADirectoryError

- NotImplemented

- NotImplementedError

- OSError

- OverflowError

- PPP

- PendingDeprecationWarning

- PermissionError

- ProcessLookupError

- RecursionError

- ReferenceError

- ResourceWarning

- RuntimeError

- RuntimeWarning

- StopAsyncIteration

- StopIteration

- SyntaxError

- SyntaxWarning

- SystemError

- SystemExit

- TabError

- TimeoutError

- True

- TypeError

- UnboundLocalError

- UnicodeDecodeError

- UnicodeEncodeError

- UnicodeError

- UnicodeTranslateError

- UnicodeWarning

- UserWarning

- ValueError

- Warning

- ZeroDivisionError

- abs

- aiter

- all

- anext

- any

- ascii

- bin

- bool

- breakpoint

- bytearray

- bytes

- callable

- chr

- classmethod

- compile

- complex

- copyright

- credits

- delattr

- dict

- dir

- divmod

- enumerate

- eval

- exec

- exit

- filter

- float

- format

- frozenset

- getattr

- globals

- hasattr

- hash

- help

- hex

- id

- input

- int

- isinstance

- issubclass

- iter

- len

- license

- list

- locals

- map

- max

- memoryview

- min

- next

- object

- oct

- open

- ord

- pow

- print

- property

- quit

- range

- repr

- reversed

- round

- set

- setattr

- slice

- sorted

- staticmethod

- str

- sum

- super

- tuple

- type

- vars

- zip

The following is a list of names that are used by Ren'Py. While in some cases it makes sense to redefine these names, one should be aware that doing so can cause obscure problems.

- ADVCharacter

- ADVSpeaker

- Action

- `AddToSet()`

- Alpha

- `AlphaBlend()`

- `AlphaDissolve()`

- `AlphaMask`

- `AnimatedValue()`

- Animation

- `At()`

- `Attribute`

- `AudioData`

- `AudioPositionValue()`

- Bar

- `BarValue`

- `Borders`

- `BrightnessMatrix`

- Button

- `Call()`

- `Camera`

- `CaptureFocus()`

- `Character()`

- `ClearFocus()`

- `Color`

- ColorMatrix

- `ColorizeMatrix`

- `ComposeTransition()`

- `Composite()`

- `Condition`

- `ConditionGroup`

- `ConditionSwitch()`

- `Confirm()`

- `Continue()`

- `ContrastMatrix`

- `CopyToClipboard()`

- `Crop()`

- `CropMove()`

- `CurrentScreenName()`

- `CycleDict()`

- `CycleField()`

- `CycleLocalVariable()`

- `CycleScreenVariable()`

- `CycleVariable()`

- DictEquality

- `DictInputValue()`

- `DictValue()`

- `DisableAllInputValues()`

- `Dissolve()`

- `DownloadSync()`

- `Drag`

- `DragGroup`

- DynamicCharacter

- `DynamicDisplayable`

- `DynamicImage`

- `EditFile()`

- `EndReplay()`

- `ExecJS()`

- FactorZoom

- `Fade()`

- FieldEquality

- `FieldInputValue()`

- `FieldValue()`

- `FileAction()`

- `FileCurrentPage()`

- `FileCurrentScreenshot`

- `FileDelete()`

- `FileJson()`

- `FileLoad()`

- `FileLoadable()`

- `FileNewest()`

- `FilePage()`

- `FilePageName()`

- `FilePageNameInputValue()`

- `FilePageNext()`

- `FilePagePrevious()`

- `FileSave()`

- `FileSaveName()`

- `FileScreenshot()`

- `FileSlotName()`

- `FileTakeScreenshot()`

- `FileTime()`

- `FileUsedSlots()`

- `Fixed()`

- `Flatten`

- `FontGroup`

- `Frame`

- `Function()`

- `Gallery`

- `GamepadCalibrate()`

- `GamepadExists()`

- `GetCharacterVolume()`

- `GetFocusRect()`

- `GetMixer()`

- `GetTooltip()`

- `Grid()`

- `HBox()`

- `Help()`

- `Hide()`

- `HideInterface()`

- `HueMatrix`

- `IdentityMatrix`

- `If()`

- `Image()`

- ImageButton

- `ImageDissolve()`

- ImageReference

- `IncrementDict()`

- `IncrementField()`

- `IncrementLocalVariable()`

- `IncrementScreenVariable()`

- `IncrementVariable()`

- Input

- `InputValue`

- `InvertMatrix`

- `InvertSelected()`

- `JSONDB`

- `Jump()`

- `Language()`

- `Layer`

- `LayeredImage`

- `LayeredImageProxy`

- `Live2D()`

- LiveComposite

- LiveCrop

- LiveTile

- `LocalVariableInputValue()`

- `LocalVariableValue()`

- `MainMenu()`

- `Matrix`

- `MixerValue()`

- `Model`

- Motion

- `MouseDisplayable`

- `MouseMove()`

- Move

- MoveFactory

- MoveIn

- MoveOut

- `MoveTransition()`

- `Movie`

- `MultiPersistent`

- `MultiRevertable`

- `MultipleTransition()`

- `MusicRoom`

- NVLCharacter

- NVLSpeaker

- `NoRollback`

- `Notify()`

- `Null`

- `NullAction()`

- `OffsetMatrix`

- OldMoveTransition

- `OpacityMatrix`

- `OpenDirectory()`

- `OpenURL()`

- PY2

- Pan

- `ParameterizedText`

- Particles

- `Pause()`

- `PauseAudio()`

- `Pixellate()`

- `Placeholder`

- Play

- `PlayCharacterVoice()`

- Position

- `Preference()`

- `PushMove()`

- `Queue()`

- `QueueEvent()`

- `QuickLoad()`

- `QuickSave()`

- `Quit()`

- `RemoveFromSet()`

- `Replay()`

- `RestartStatement()`

- `Return()`

- Revolve

- RevolveInOut

- `RollForward()`

- `Rollback()`

- `RollbackToIdentifier()`

- `RotateMatrix`

- RotoZoom

- RoundRect

- `SaturationMatrix`

- `ScaleMatrix`

- `ScreenVariableInputValue()`

- `ScreenVariableValue()`

- `Screenshot()`

- `Scroll()`

- `SelectedIf()`

- `SensitiveIf()`

- `SepiaMatrix()`

- Set

- `SetCharacterVolume()`

- `SetDict()`

- `SetField()`

- `SetLocalVariable()`

- `SetMixer()`

- `SetMute()`

- `SetScreenVariable()`

- `SetVariable()`

- `SetVoiceMute()`

- `Show()`

- `ShowMenu()`

- `ShowTransient()`

- `ShowingSwitch()`

- `SideImage()`

- SizeZoom

- `Skip()`

- `SlottedNoRollback`

- `SnowBlossom()`

- `Solid`

- Speaker

- SplineMatrix

- SplineMotion

- `Sprite`

- `SpriteManager`

- `Start()`

- `StaticValue()`

- Stop

- `Style`

- `StylePreference()`

- SubTransition

- `Swing()`

- `Text`

- TextButton

- `Tile`

- `TintMatrix`

- `ToggleDict()`

- `ToggleField()`

- `ToggleFocus()`

- `ToggleLocalVariable()`

- `ToggleMute()`

- `ToggleScreen()`

- `ToggleScreenVariable()`

- `ToggleSetMembership()`

- `ToggleVariable()`

- `ToggleVoiceMute()`

- `Tooltip`

- `Transform`

- TransformMatrix

- `UploadSync()`

- `VBox()`

- `VariableInputValue()`

- `VariableValue()`

- Viewport

- VoiceInfo

- `VoiceReplay()`

- Window

- `With()`

- `XScrollValue()`

- `YScrollValue()`

- Zoom

- ZoomInOut

- `absolute()`

- absolute_import

- `achievement`

- `adv`

- adv_narrator

- `alt`

- anim

- audio

- basestring

- bchr

- `blinds`

- bord

- `bubble`

- `build`

- `center`

- centered

- color

- `config`

- default

- default_transition

- `defaultdict`

- `define`

- `director`

- dissolve

- division

- `ease`

- easeinbottom

- easeinleft

- easeinright

- easeintop

- easeoutbottom

- easeoutleft

- easeoutright

- easeouttop

- extend

- `fade`

- `gui`

- `hpunch`

- hyperlink_function

- hyperlink_sensitive

- hyperlink_styler

- `iap`

- icon

- `im`

- incdir

- `irisin`

- irisout

- `layeredimage`

- layout

- `left`

- library

- `main_menu`

- `menu`

- `mouse_visible`

- `move`

- moveinbottom

- moveinleft

- `moveinright`

- moveintop

- moveoutbottom

- moveoutleft

- `moveoutright`

- moveouttop

- `name_only`

- `narrator`

- nvl

- `nvl_clear()`

- nvl_clear_next

- nvl_erase

- `nvl_hide()`

- nvl_list

- `nvl_menu()`

- nvl_narrator

- `nvl_show()`

- nvl_show_core

- nvl_variant

- nvl_window

- `offscreenleft`

- `offscreenright`

- os

- `persistent`

- `pixellate`

- `position()`

- predict_menu

- predict_say

- `preferences`

- print_function

- pushdown

- pushleft

- `pushright`

- pushup

- pygame_sdl2

- pystr

- python_dict

- python_list

- python_object

- python_set

- raw_input

- `renpy`

- renpy_json

- `reset`

- `right`

- `save_name`

- `say`

- shaderdoc

- slideawaydown

- `slideawayleft`

- slideawayright

- slideawayup

- slidedown

- `slideleft`

- slideright

- slideup

- `squares`

- srcdir

- store

- `style`

- suppress_overlay

- sv

- swing

- sys

- textshader

- theme

- tobytes

- toggle_skipping

- top

- `topleft`

- `topright`

- `truecenter`

- `ui`

- unicode

- unicode_literals

- `updater`

- vcentered

- `voice()`

- `voice_can_replay()`

- `voice_replay()`

- `voice_sustain()`

- `vpunch`

- wipedown

- `wipeleft`

- wiperight

- wipeup

- with_statement

- xrange

- `zoomin`

- `zoominout`

- `zoomout`