WalkSpeed is a property of the Humanoid object that determines the model's speed when being controlled by a player or when MoveTo() is activated. WalkSpeed is most often changed for running or sprinting mechanics, or lowered as a part of crouching mechanics.
The default WalkSpeed for Roblox characters is 16 studs/second. A higher number equals a higher speed, and a lower number equals a lower speed. Formerly, if the WalkSpeed number was negative, controls would be reversed. Now, it prevents the character from moving at all. If the WalkSpeed is high enough, a player can run through walls depending on how thick they are (i.e. having a speed of 250 might cause a user to pass through a 1-stud-thick wall). Increasing the WalkSpeed will also increase the distance a player can jump.
script.Parent.Touched:connect(function(part) -- make sure the part still exists if not part.Parent then return end -- make sure it's a humanoid local h = part.Parent:FindFirstChild("Humanoid") if not h then return end -- change to five times faster than default speed h.WalkSpeed = 16 * 5 end)