I'm making a game and one part is if you are moving/running and you press left shift an aura will appear and you'll go faster, like in Sonic games. I tried one script, but when I used it it rarely worked. Sometimes I would let go of left shift and there would be a long delay before the aura went away. This script didn't include the part where you have to be running though. The aura also had particles on it and I made it so they would appear with the aura when left shift was pressed, but they wouldn't appear. I'm using this for a StarterCharacter so the script is a local script in StarterCharacterScripts. If anyone knows how to do this so it works all the time then I would appreciate it!

Thanks.

Hello Ben. I think I found the solution to your problem.

What we need to do is create a LocalScript(so we can access the LocalPlayer) and place it into our StarterPack, as it's the pack we start off with when we join.

Now you need to put some variables into that script.

local plr = game.Players.LocalPlayer -- defines player
local char = plr.Character or plr.CharacterAdded:Wait() -- defines character
local uis = game:GetService("UserInputService") -- shorter defintion
local walk = 16 -- our walk value
local sprint = 32 -- our running/sprinting value

Now that we have sorted all of that out, it's time to begin functioning.

We're going to firstly call some functions(InputBegan and InputEnded)

uis.InputBegan:Connect(function(key)
	
end)

uis.InputEnded:Connect(function(key)
	
end)

Then we're going to check if whoever is clicking the button is clicking LShift(Left Shift)

uis.InputBegan:Connect(function(key)
	if key.KeyCode == Enum.KeyCode.LeftShift then
		
	end
end)

uis.InputEnded:Connect(function(key)
	if key.KeyCode == Enum.KeyCode.LeftShift then
		
	end
end)

Now that we now know what button they are pressing, we're going to run some code if they are pressing that button.

In this case we'll be using our 'walk' and 'sprint' value.

uis.InputBegan:Connect(function(key)
	if key.KeyCode == Enum.KeyCode.LeftShift then
		char.Humanoid.WalkSpeed = sprint
	end
end)

uis.InputEnded:Connect(function(key)
	if key.KeyCode == Enum.KeyCode.LeftShift then
		char.Humanoid.WalkSpeed = walk
	end
end)

Tadahh!!! All you have to do is now put the variables we've listed from above into the script and then you're officially done! You can insert Aura's if you wish through the Server to the Client, or the Server in general. If you do not know how to do that, check out videos specialising in the topic, 'RemoteEvents'.

local plr = game.Players.LocalPlayer
local char = plr.Character or plr.CharacterAdded:Wait()
local uis = game:GetService("UserInputService")
local walk = 16
local sprint = 32

uis.InputBegan:Connect(function(key)
	if key.KeyCode == Enum.KeyCode.LeftShift then
		char.Humanoid.WalkSpeed = sprint
	end
end)

uis.InputEnded:Connect(function(key)
	if key.KeyCode == Enum.KeyCode.LeftShift then
		char.Humanoid.WalkSpeed = walk
	end
end)

I hope I helped, if I did please click 'Accept' to show me support!