FMath::RandRange

function Core Since unknown

#include "Math/UnrealMathUtility.h"

Access: public Specifiers: static

Description

Returns a random integer in the inclusive range [Min, Max]. A float overload (FMath::FRandRange) exists for continuous ranges.

Signature

static inline int32 RandRange(int32 Min, int32 Max)

Parameters

Name	Type	Description	Default
Min	int32	Minimum value of the range, inclusive.	—
Max	int32	Maximum value of the range, inclusive.	—

Return Type

int32

Caveats & Gotchas

• The integer overload is inclusive on both ends — RandRange(0, 1) returns either 0 or 1 with equal probability.
• When passing float literals, the compiler will select the float overload (FRandRange) rather than int32. Prefer explicit int32 casts or use FMath::FRandRange directly to make intent clear.
• Uses a global seed shared across the process. For deterministic or per-instance random sequences (AI, procedural generation), use FRandomStream instead.
• Not thread-safe — avoid calling from multiple threads simultaneously without your own synchronisation.

Example

Random loot drop and random spawn offset C++

// Random integer in [1, 6] — simulating a dice roll
int32 DiceRoll = FMath::RandRange(1, 6);

// Random float in [0.5, 2.0] — using the float overload
float RandomPitch = FMath::RandRange(0.5f, 2.0f);

// Deterministic version using FRandomStream (preferred for reproducible results)
FRandomStream Stream(42);
int32 DeterministicRoll = Stream.RandRange(1, 6);

Version History

Introduced in: unknown

Version	Status	Notes
5.6	stable	—

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