#summary List of gameplay-related functions in the Lua API

= Lua API: Gameplay functions =
This page is a list of all gameplay-related functions in the [LuaAPI Lua API].

<wiki:toc max_depth="3" />

== `GameFlags` functions ==
`GameFlags` are boolean settings of the game. You should call these functions only in the `onGameInit` [LuaEvents event]. See [LuaGlobals#GameFlags].

=== <tt>!ClearGameFlags()</tt> ===
Disables *all* !GameFlags.

=== <tt>!DisableGameFlags(gameflag, ...)</tt> ===
Disables the listed !GameFlags, without changing the status of other !GameFlags.

=== <tt>!EnableGameFlags(gameflag, ...)</tt> ===
Enables the listed !GameFlags, without changing the status of other !GameFlags. In missions, no !GameFlags are set initially.

=== <tt>!GetGameFlag(gameflag)</tt> ===
Returns `true` if the specified gameflag is enabled, otherwise `false`.

== Turns ==
=== <tt>SkipTurn()</tt> (0.9.24) ===
Forces the current hedgehog to skip its turn.

=== `EndTurn([noTaunts])` (0.9.23) ===
Ends the current turn immediately.

Normally, a “Coward” taunt may be played and an announcer message may be shown (depending on the situation). Set the optional `noTaunts` parameter to `true` to force the engine to never play a taunt or show a message. `noTaunts` is `false` by default.

=== <tt>Retreat(time [, respectGetAwayTimeFactor)</tt> (0.9.25) ===
Forces the current turn into the retreating phase, as if the hog made an attack. That is, the current hedgehog is unable to attack or select a weapon, only movement is possible until the retreat time is up.

The retreat time must be set with `time` in milliseconds. By default, this time is automatically multiplied with get-away time percentage from the game scheme for seamless integration with schemes. If you want to ignore the game scheme for some reason and set the retreat time no matter what, set `respectGetAwayTimeFactor` to `false`.

If the current hedgehog was busy doing an attack, the attack is aborted, no shot is made. If this function is called in the ready phase of a turn, the ready phase continues normally, but the turn will begin in the retreat phase instead.

Note: If you want the turn to end instantly, it is recommended to use `EndTurn` instead.

=== <tt>!SetTurnTimeLeft(newTurnTimeLeft)</tt> (0.9.25) ===
Set the remaining turn time in milliseconds. The current remaining turn time can be read from the variable `TurnTimeLeft`.

=== <tt>!SetReadyTimeLeft(newReadyTimeLeft)</tt> (0.9.25) ===
Set the remaining ready time in milliseconds. This function should only be called in onNewTurn. The current remaining ready time can be read from the variable `ReadyTimeLeft`.

=== <tt>!SetTurnTimePaused(isPaused)</tt> (0.9.25) ===
Pauses the turn time indefinitely if `isPaused` is set to `true`, disabled the turn time pause if `isPaused` is set to `false`.

=== <tt>!GetTurnTimePaused()</tt> (0.9.25) ===
Returns `true` if the turn time is currently paused by `SetTurnTimePaused`, otherwise returns `false`.

=== <tt>!EndGame()</tt> ===
Makes the game end.

== Environment ==
=== <tt>!SetGravity(percent)</tt> ===
Changes the current gravity of the game in percent (relative to default, integer value).
Setting it to 100 will set gravity to default gravity of Hedgewars, 200 will double it, etc.

=== <tt>!GetGravity()</tt> ===
Returns the current gravity in percent.

=== <tt>!SetWaterLine(waterline)</tt> ===
Sets the water level (`WaterLine`) to the specified y-coordinate.

=== <tt>!SetWind(windSpeed)</tt> ===
Sets the current wind in the range of -100 to 100 inclusive. Use together with `gfDisableWind` for full control.

=== <tt>!GetWind()</tt> (0.9.24) ===
Returns current wind, expressed as a floating point number between -100 to 100 inclusive. Note there may be rounding errors.

=== <tt>!SetMaxBuildDistance(distInPx)</tt> ===
Sets the maximum building distance for of girders and rubber bands in pixels to `distInPx`. If `distInPx` is `0`, the limit is disabled. If called without arguments, the distance will be reset to the default value.

=== <tt>Explode(x, y, radius[, options])</tt> (0.9.24) ===
Cause an explosion or erase land, push or damage gears.

By default, an explosion destroys a circular piece of land and damages and pushes gears in its radius.

The explosion occurs at coordinates `(x, y)` with the given `radius`. Assuming 100% damage, the explosion damage at the center equals the explosion radius.

The explosion will also have a visual effect (by spawning an explosion visual gear), unless the radius is very small.

`options` is a bitmask which can be used to tweak how the explosion behaves:

|| *Flag* || *Meaning* ||
|| `EXPLAutoSound` || Plays an appropriate sound ||
|| `EXPLNoDamage` || Deal no damage to gears ||
|| `EXPLDoNotTouchHH` || Do not push hedgehogs ||
|| `EXPLDoNotTouchAny` || Do not push any gears ||
|| `EXPLDontDraw` || Do not destroy land ||
|| `EXPLForceDraw` || Destroy land, even if `gfSolidLand` is active ||
|| `EXPLNoGfx` || Do not show an explosion animation and do not shake the screen ||
|| `EXPLPoisoned` || Poison all hedgehogs in explosion radius ||

`options` is assumed to be `EXPLAutoSound` by default. Set `options` to 0 to disable all flags.

Examples:
<code language="lua">
-- Simple explosion at (100, 50) with radius 50
Explode(100, 50, 50)

-- Simple explosion without sound
Explode(100, 50, 50, 0)

-- Fake explosion which only pushes gears but deals no damage to gears and terrain
Explode(500, 1000, 50, EXPLAutoSound + EXPLNoDamage + EXPLDontDraw)

-- Erase a circle of land without side effects
Explode(500, 100, 100, EXPLNoDamage + EXPLDoNotTouchAny + EXPLNoGfx)
</code>

== Ammo ==
=== <tt>!SetAmmo(ammoType, count, probability, delay, numberInCrate)</tt> ===
This updates the settings (initial ammo, crate probability, etc.) for a specified [AmmoTypes ammo type]. This must only be used in the `onAmmoStoreInit()` [LuaEvents event handler]. In other places, this function will not work.

In Lua missions, for *all* ammo types, the ammo count, probability, delay and number in crates is set to 0 initially. Note: This also includes skip!

Parameters:

 * `ammoType`: Ammo type to be set
 * `count`: Initial ammo count. 9 = infinite
 * `probability`: Crate probability. Max. value is 9. 0 = never
 * `delay`: Number of rounds this ammo is delayed
 * `numberInCrate`: Amount of ammo in a crate

Example:

<code language="lua">    SetAmmo(amShotgun, 9, 0, 0, 0) -- unlimited amount of shotgun ammo for players
    SetAmmo(amGrenade, 0, 0, 0, 3) -- crates should contain always three grenade
    SetAmmo(amSkip, 9, 0, 0, 0) -- enable skip</code>

Hint: It is recommended to always enable skip in missions. Only in exceptional circumstances you should choose to not enable skip.

=== <tt>!GetAmmo(ammoType)</tt> ===
Returns ammo settings (initial ammo, crate probability, etc.) for a specified [AmmoTypes ammo type]. This function is analogue to `SetAmmo`.

This function returns four numbers, in this order: initial ammo count, probability, delay and number in crate. These values correspond to the parameters 2-5 provided in `SetAmmo` and have the same meaning.

Example:

<code language="lua">count, prob, delay, numberInCrate = GetAmmo(amGrenade) -- Get ammo settings of amGrenade</code>

=== <tt>!SetAmmoDelay(ammoType, delay)</tt> ===
Changes the delay of a specified [AmmoTypes Ammo Type].

=== <tt>!SetAmmoTexts(ammoType, name, caption, description [, showExtra])</tt> (0.9.23) ===
Allows you to overwrite the displayed name and tooltip descriptions of a given ammo type. This function must only be called either inside the `onGameStart` callback function, or after the engine has called `onGameStart`.

 * `ammoType`: The ammo type to set the text for
 * `name`: Name of the ammo type (e.g. “Grenade” for `amGrenade`), affects both name in ammo menu and in the “ticker” message on the screen top.
 * `caption`: The second line in the ammo menu (below the title). E.g. “Timed grenade” for `amGrenade`.
 * `description`: Description text in ammo menu, below the caption.
 * `showExtra`: If `false` the special “extra” text line like “Weapon is not yet available” or “Weapon does not end turn” will be suppressed

`title`, `caption`, `description` can be `nil`, in which case they will be reverted to the engine default value. This function returns `nil`.

Example:
<code language="lua">
-- Overwrites bazooka name and description
SetAmmoTexts(amBazooka, "Spoon Missile", "Crazy weapon", "This crazy weapon looks like a spoon and explodes on impact.|Attack: Hold to launch with more power")</code>

=== <tt>!SetAmmoDescriptionAppendix(ammoType, descAppend)</tt> (0.9.23) ===
Will set a string `descAppend` to be appended below the “core” description (ammo tooltip) of the specified `ammoType`, without changing the ordinary description.
Note that calling this function always sets the complete appended string, you can't use this function to append multiple texts in row.

This function is recommended if you have tweaked an existing ammo type only a little and want to keep the original description intact as much as possible.

Example:
<code language="lua">
-- Appends a text to the ammo tooltip of the bazooka but leaves name and main description intact
SetAmmoTexts(amBazooka, "This weapon deals double the damage than usually.")</code>

=== <tt>!AddAmmo(gearUid, ammoType, ammoCount)</tt> ===
Adds `ammoType` to the specified gear. The amount added is determined by the arguments passed via `SetAmmo()` in the `onAmmoStoreInit()` [LuaEvents event handler]. `ammoCount` is an optional parameter. If this is set, the ammo will *not* be added, but instead set to `ammoCount`. A value of `0` will remove the weapon, a value of `AMMO_INFINITE` will give infinite ammo.

Note: By default, ammo is per-team, so calling `AddAmmo` for a hedgehog will give the ammo for the whole team. The game flags `gfPerHogAmmo` and `gfSharedAmmo` change how ammo is managed in the game, so these game flags also affect `AddAmmo`.

=== <tt>!GetAmmoName(ammoType [, ignoreOverwrite ])</tt> (0.9.23) ===
Returns the localized name for the specified `ammoType`, taking an ammo name overwritten by `SetAmmoTexts` into account. If `ignoreOverwrite` is `true`, this function will always return the original ammo name of the weapon and ignores names which may have been overwritten by `SetAmmoTexts`.

== Map ==
=== <tt>!MapHasBorder()</tt> ===
Returns `true`/`false` if the map has a border or not.

=== <tt>!TestRectForObstacle(x1, y1, x2, y2, landOnly)</tt> ===
Checks the rectangle between the given coordinates for possible collisions. Set `landOnly` to `true` if you don’t want to check for collisions with gears (hedgehogs, etc.).

=== <tt>!PlaceGirder(x, y, frameIdx)</tt> ===
Attempts to place a girder with centre points `x`, `y` and a certain length and orientation, specified by `frameIdx`. The girder can only be placed in open space and must not collide with anything so this function may fail. It will return `true` on successful placement and `false` on failure.

These are the accepted values for `frameIdx`:

|| *`frameIdx`* || *Length* || *Orientation* ||
|| 0 || short || horizontal ||
|| 1 || short || decreasing right ||
|| 2 || short || vertical ||
|| 3 || short || increasing right ||
|| 4 || long || horizontal ||
|| 5 || long || decreasing right ||
|| 6 || long || vertical ||
|| 7 || long || increasing right ||

=== <tt>!PlaceRubber(x, y, frameIdx)</tt> (0.9.23) ===
Attempts to place a rubber with centre points `x`, `y` and a certain orientation, specified by `frameIdx`. The rubber can only be placed in open space and must not collide with anything so this function may fail. It will return `true` on successful placement and `false` on failure.

These are the accepted values for `frameIdx`:

|| *`frameIdx`* || *Orientation* ||
|| 0 || horizontal ||
|| 1 || decreasing right ||
|| 2 || vertical ||
|| 3 || increasing right ||

=== <tt>!PlaceSprite(x, y, sprite, frameIdx, tint, behind, flipHoriz, flipVert, [, landFlag, ...])</tt> ===
Places a [Sprites sprite] at the specified position (`x`, `y`) on the map, it behaves like terrain then. Unlike `PlaceGirder`, this function does not check for collisions, so the sprite can be placed anywhere within map boundaries. The function returns `true` if the placement was successful, `false` otherwise. `frameIdx` is the frame index starting by 0. `frameIdx` is used if the sprite consists of several sub-images. Only a subset of the sprites is currently supported by this function:

 * `sprAmGirder`
 * `sprAmRubber`
 * `sprAMSlot`
 * `sprAMAmmos`
 * `sprAMAmmosBW`
 * `sprAMCorners`
 * `sprHHTelepMask`
 * `sprTurnsLeft`
 * `sprSpeechCorner`
 * `sprSpeechEdge`
 * `sprSpeechTail`
 * `sprTargetBee`
 * `sprThoughtCorner`
 * `sprThoughtEdge`
 * `sprThoughtTail`
 * `sprShoutCorner`
 * `sprShoutEdge`
 * `sprShoutTail`
 * `sprBotlevels`
 * `sprIceTexture`
 * `sprCustom1`
 * `sprCustom2`

`tint` is for an RGBA colouring to apply, this works about the same as `Tint` in gears. If `nil`, the original color is used.

`behind` indicates the sprite should not replace existing land.

`flipHoriz` and `flipVert` are for mirroring the sprite vertically and horizontally before placing, respectively.

The 9th and later arguments specify land flags (see the constants section) to be used for the newly created terrain. If omitted, `lfNormal` is assumed.

Example:

<code language="lua">PlaceSprite(2836, 634, sprAmGirder, 5)
-- Places the girder sprite as normal terrain at (2836, 634). The `frameIdx` 5 is for the long decreasing right girder.</code>
<code language="lua">PlaceSprite(1411, 625, sprAmRubber, 1, nil, nil, nil, nil, lfBouncy)
-- Places the rubber band sprite as bouncy terrain at (2836, 634). The `frameIdx` 1 is for the decreasing right rubber band.</code>

=== <tt>!EraseSprite(x, y, sprite, frameIdx, eraseOnLFMatch, onlyEraseLF, flipHoriz, flipVert, [, landFlag, ...])</tt> ===
Erases a [Sprites sprite] at the specified position (`x`, `y`) on the map. `frameIdx` is the frame index starting by 0. `sprite`, `frameIdx`, `flipHoriz` and `flipVert` behave the same as in `PlaceSprite`. For `sprite`, the same subset of sprites is permitted.

Set `eraseOnLFMatch` to `true` to erase all land for a pixel that matches any of the passed in land flags.  This is useful if, for example, an `lfBouncy` sprite was placed “behind” land using `PlaceSprite` and you want to remove it without destroying the non-bouncy terrain.

Set `onlyEraseLF` to `true` to only remove specific land flags. If for example a sprite consists of `lfIndestructible` and `lfBouncy`, and you call `EraseSprite` with `onlyEraseLF` and `lfIndestructible` set, the sprite will remain bouncy but can be destroyed.  You can use this to entirely remove all land flags from a sprite—at this point the sprite will be visual only, painted on the map but with no collision.

Examples:

<code language="lua">EraseSprite(2836, 634, sprAmGirder, 5)
-- Removes the girder sprite at (2836, 634). The frameIdx 5 is for the long decreasing right girder.</code>
<code language="lua">EraseSprite(1411, 625, sprAmRubber, 1, true, true, nil, nil, lfIndestructible)
-- Removes indestructibility from a rubber band sprite at (2836, 634). The frameIdx 1 is for the decreasing right rubber band.</code>

=== <tt>!AddPoint(x, y [, width [, erase] ])</tt> ===
This function is used to draw your own maps using Lua. The maps drawn with this are of type “hand-drawn”.

The function takes a `x`,`y` location, a `width` (means start of a new line) and `erase` (if `false`, this function will draw normally, if `true`, this function will erase drawn stuff).

This function must be called within `onGameInit`, where `MapGen` has been set to `mgDrawn`. You also should call `FlushPoints` when you are finished with drawing.

See [LuaDrawning] for some examples.

=== <tt>!FlushPoints()</tt> ===
Makes sure that all the points/lines specified using `AddPoint` are actually applied to the map. This function must be called within `onGameInit`.

== Current hedgehog ==

=== <tt>!GetCurAmmoType()</tt> ===
Returns the currently selected [AmmoTypes Ammo Type].

=== <tt>!SwitchHog(gearUid)</tt> ===
This function will switch to the hedgehog with the specifiedd `gearUid`.

=== <tt>!SetWeapon(ammoType)</tt> ===
Sets the selected weapon of `CurrentHedgehog` to one of the [AmmoTypes Ammo Type].

Examples:

<code language="lua">
  SetWeapon(amBazooka) -- select the bazooka (if hog has one)
</code>
<code language="lua">
  SetWeapon(amNothing) -- unselects the weapon.
</code>

=== <tt>!SetNextWeapon()</tt> ===
This function makes the current hedgehog switch to the next weapon in list of available weapons. It can be used for example in trainings to pre-select a weapon.

=== <tt>!SetInputMask(mask)</tt> ===
Masks specified player input. `mask` is a gear message bitmask (see [GearMessages]). This means that Hedgewars ignores certain player inputs, such as walking or jumping. However, the controls [LuaEvents event functions] such as `onAttack` or `onLeft` will still be called, even when masked.

Example: 
<code language="lua">    -- masks the long and high jump commands, making it impossible to jump
SetInputMask(band(0xFFFFFFFF, bnot(gmLJump + gmHJump))) 
    -- clears input mask, allowing player to take actions
    SetInputMask(0xFFFFFFFF) 
		</code>
*Note*: Using the input mask is an effective way to script uninterrupted cinematics, or create modes such as No Jumping.

*Note*: This function is used internally in the Animate [LuaLibraries library].

See also [GearMessages].

=== <tt>!GetInputMask()</tt> ===
Returns the current input mask of the player.

=== <tt>!SetVampiric(bool)</tt> (0.9.24) ===
Toggles vampirism mode for this turn. Set `bool` to `true` to enable (same effect as if the hedgehog has used Vampirism), `false` to disable.

=== <tt>!GetVampiric()</tt> (0.9.25) ===
Returns true if vampirism mode is currently active.

=== <tt>!SetLaserSight(bool)</tt> (0.9.24) ===
Toggles laser sight for this turn. Set `bool` to `true` to enable (same effect as if the hedgehog has used Laser Sight), `false` to disable.

=== <tt>!GetLaserSight()</tt> (0.9.25) ===
Returns true if laser sight (as utility) is currently active. The sniper rifle's built-in laser sight does not count.

=== <tt>!EnableSwitchHog()</tt> (0.9.25) ===
Enable hog switching mode for the current hedgehog. This function should be called while the hedgehog is standing on solid ground (`GetFlightTime` returns 0).

Internally, this tries to spawn a `gtSwitcher` gear which, as long it exists, handles the hog switching. You can delete this gear to stop the hog switching prematurely. If there already is a `gtSwitcher` gear, no additional gear is spawned.

On success, returns the `gtSwitcher` gear being spawned or, if hog switching mode is already active, returns the exsting gear. On failure, returns `nil`.

== Clans and teams ==
=== <tt>!AddTeam(teamname, color, grave, fort, voicepack, flag)</tt> ===

Adds a new team.

You *must* call it only in `onGameInit`.
You *must* add at least one hedgehog with `AddHog` after calling this. The engine does not support empty teams.
`AddTeam` is only supported for singleplayer missions. You *must not* call this function in multiplayer.

Arguments:

 * `teamname`: The name of the team.
 * `color`: Team color, usually a number from -9 to -1 (see below)
 * `grave`: The name of the team’s grave (equals file name without the suffix)
 * `fort`: The name of the team’s fort (equals file name without the suffix and without the letter “L” or “R” before that suffix)
 * `voicepack`: The name of the team’s voice pack (equals the directory name)
 * `flag`: Optional argument for the name of the team’s flag (equals file name without the suffix). If set to `nil`, the flag “hedgewars” is used.

==== Clan color ====
Each team must have a color. The color also determines clan membership: Teams with equal color are in the same clan.

The team color is specified as a number from -9 to -1. This will select one of the 9 possible team colors as specified in the player's settings. As the actual colors are set by the player, you can't predict them, but you can usually trust these defaults:

 * `-1`: red
 * `-2`: blue
 * `-3`: cyan
 * `-4`: purple
 * `-5`: magenta
 * `-6`: green
 * `-7`: orange
 * `-8`: brown
 * `-9`: yellow

An older (and now discouraged) method of specifying the color is by hardcoding it as an RGB color (i.e. `0xDD0000`). This practice is now strongly discouraged because it will ignore the player-chosen color (which is *bad* for players with color blindness) and in 99% of cases you don't need it anyway. It should be only used for testing and debugging. 

==== Example ====

<code language="lua">AddTeam("team 1", -1, "Simple", "Tank", "Default", "hedgewars")
--[[ Adds a new team with name “team 1”, the first default color (usually red), the grave “Simple”,
the fort “Tank” the voicepack “Default” and the flag “hedgewars”. ]]</code>

=== <tt>!AddMissionTeam(color)</tt> (0.9.25) ===
Adds a new team using the player-chosen team identity when playing a singleplayer mission. Does not work in multiplayer.

This function is very similar to `AddTeam`. Team settings like team name and flag will be taken from the player-chosen team.
You only need to specify the clan color, which has the same meaning as in `AddTeam`.

Use `AddMissionHog` or `AddHog` afterwards to add hedgehogs for this team. You can mix `AddMissionHog` and `AddHog` as you wish.

Example:
<code language="lua">-- Add mission team with default clan color
AddMissionTeam(-1)</code>

=== <tt>!GetTeamName(teamIdx)</tt> (0.9.24) ===
Returns the name of the team with the index `teamIdx`. `teamIdx` is a number between 0 and `TeamsCount-1`.

=== <tt>!GetTeamIndex(teamname)</tt> (0.9.24) ===
Returns the team index (number between 0 and `TeamsCount-1`) of the team with the name `teamName`.

=== <tt>!GetTeamClan(teamname)</tt> (0.9.24) ===
Returns the clan ID of the team with the given `teamName`.

=== <tt>!DismissTeam(teamname)</tt> ===
Vaporizes all the hogs of the team with the given team name in a puff of smoke.

This function must not be called while it's the team's turn.

=== <tt>!SetTeamLabel(teamname[, label])</tt> (0.9.24) ===
Set or remove a label for the team with the given team name. The label is a string and will be displayed next to the team's health bar.

If `label` is `nil`, the label will be removed.

There's a special case: If the AI Survival game modifier is active, the AI kill counter will be replaced by the custom team label if it has been set. If `label` is set to `nil`, the default AI counter is shown again.

Use this to display a score, power value or another important team attribute. There's no hard length limit, but please try to keep it as short as possible to avoid visual clutter.

=== <tt>SetTeamPassive(teamname, isPassive)</tt> (1.0.0) ===
Mark a team as passive if `isPassive` is `true`. Passive teams do not participate in the game and are treated like frozen teams. When determining the team order, passive teams are completely ignored.

=== <tt>!GetClanColor(clan)</tt> ===
Returns the RGBA color of the chosen clan by its number. The color data type is described in [LuaOverview#Color].

=== <tt>!SetClanColor(clan, color)</tt> ===
Sets the RGBA color of the chosen clan by its number. The color data type is described in [LuaOverview#Color]. The new clan color *must* be different from the color of all clans (you can't use this function to change clan memberships of teams).

Note: The stats graph does not support changing clan colors. If the clan colors change in mid-game, the graph might get confused and shows weird stuff. You may want to turn off the graph with if this is the case (see `SendHealthStatsOff`).

== Campaign management ==
=== <tt>!SaveCampaignVar(varname, value)</tt> ===
Stores the value `value` (a string) into the campaign variable `varname` (also a string). Campaign variables allow you to save progress of a team in a certain campaign. Campaign variables are saved on a per-team per-campaign basis. They are written into the team file (see [ConfigurationFiles#TeamName.hwt]).

There are some special campaign variables which are used by Hedgewars to determine which missions to display in the campaign menu. This is described [ConfigurationFiles#%5BCampaign%20%3CCAMPAIGN_NAME%3E%5D here].

=== <tt>!GetCampaignVar(varname)</tt> ===
Returns the value of the campaign variable `varname` as a string. See also `SaveCampaignVar`.

=== <tt>!SaveMissionVar(varname, value)</tt> (0.9.25) ===
Stores the value `value` (a string) into the mission variable `varname` (also a string). A mission variable is like a campaign variable, but it applies for singleplayer missions only (Training/Challenge/Scenario), excluding campaign missions.

=== <tt>!GetMissionVar(varname)</tt> (0.9.25) ===
Returns the value of the mission variable `varname` as a string. See also `SaveMissionVar`.

== Randomness ==
=== <tt>!GetRandom(number)</tt> ===
Returns a randomly generated number in the range of 0 to number - 1. This random number uses the game seed, so is synchronised, and thus safe for multiplayer and saved games. Use `GetRandom` for anything that could impact the engine state. For example, a visual gear could simply use Lua’s `math.random`, but adding a regular gear should use `GetRandom`.