Hey, NuclearEntity here! You know those red killbricks in obbies? Well in this tutorial I'm going to show you how to create one!

Example of a killbrick.

Steps

These are all the steps to making your killbrick!

Step 1

First, insert a part and change the properties to how you want it to be.

Step 2

Insert a script inside the part you created, and open it.

Step 3

Scripting time! First type the following in:

local KillBrick = script.Parent

Step 4

Let's now add an event that will fire every time something hits the part.

KillBrick.Touched:Connect(function(hit)
    
end)

Step 5

Now we are going to code the main part of this script. First, inside the event we made, we will check if hit's parent contains a humanoid. This is important because we only want our code to kill players and NPCs. Then, we will check if the player/NPC's humanoid's health is greater than 0. We don't want our killbrick killing players/NPCs that are already dead! If the health is greater than 0, then we damage it by its MaxHealth(so it kills it).

local humanoid = hit.Parent:FindFirstChildOfClass("Humanoid")
if humanoid ~= nil then
    if humanoid.Health > 0 then
        humanoid:TakeDamage(humanoid.MaxHealth)
    end
end

Final Result

If you coded it correctly, it should look like this:

local KillBrick = script.Parent

KillBrick.Touched:Connect(function(hit)
	local humanoid = hit.Parent:FindFirstChildOfClass("Humanoid")
    if humanoid ~= nil then
        if humanoid.Health > 0 then
            humanoid:TakeDamage(humanoid.MaxHealth)
        end
    end
end)

Conclusion

Hope it helps! If you have any errors, comment it. ~NuclearEntity