Create Player Hazards | Documentation

Hazard objects decrease the health of players when they touch them. As a simple starting point, this section of the tutorial teaches you how to create one large invisible part at the same level as the water in your experience, so that falling into the hazard changes the player's health to zero and respawns them back to the start of the experience.

Create a Basic Water Hazard

To create the basic water hazard:

In the Explorer window, add a new folder into the World folder, then rename it Hazards. Ensure that the name is spelled correctly with the correct casing, otherwise the code won't work.
In the Hazards folder, insert a block part and rename it Hazard.
Move and scale the part to cover the water line around the island and platforms. For example, the sample Island Jump - Scripting experience sets Size to 825, 1, 576 and CFrame.Position to 174, -6.5, 38.
Select the part, then in the Properties window, configure the following properties so the hazard is invisible, and players can pass right through it:
- Set Transparency to 1. This makes the hazard invisible, so that the actual water appears to be the hazard.
- Disable CanCollide. This tells the engine that other parts can pass through the hazard uninterrupted, meaning players can fall through the hazard.
- Enable Anchored. This tells the engine to never change the position of the hazard due to any physics-related simulation, meaning that players can touch the hazard without affecting its location.
Create a Script in ServerScriptService, then rename it to HazardService.

Replace the default code with the following code:


local Players = game:GetService("Players")
local Workspace = game:GetService("Workspace")

local hazardsFolder = Workspace.World.Hazards
local hazards = hazardsFolder:GetChildren()

local function onHazardTouched(otherPart)
  local character = otherPart.Parent
  local player = Players:GetPlayerFromCharacter(character)
  if player and character.Humanoid then
    character.Humanoid.Health = 0
  end
end

for _, hazard in hazards do
  hazard.Touched:Connect(onHazardTouched)
end

Code Explanation

The HazardService has many similarities to CoinService. However, instead of collecting a coin, the player has their health set to 0 when they touch a hazard.

Feel free to modify, add, or remove hazard objects in your experience to create unique obstacles. As long as they are contained in the Hazards folder, the code loop connects the event handler to all of your hazards.

Connect to the Player Lifecycle

The player lifecycle represents events that occur when players interact in your experience, such as joining, leaving, or respawning. You need to connect handlers to these events to appropriately execute logic for each major lifecycle event. In the CoinService script, copy and paste the following code at the bottom of the script:


local function onPlayerAdded(player)
  -- Reset player coins to 0
  updatePlayerCoins(player, function(_)
    return 0
  end)

  player.CharacterAdded:Connect(function(character)
    -- WaitForChild would stop the player loop, so below should be done in a separate thread
    task.spawn(function()
      -- When a player dies
      character:WaitForChild("Humanoid").Died:Connect(function()
        -- Reset player coins to 0
        updatePlayerCoins(player, function(_)
          return 0
        end)
      end)
    end)
  end)
end

-- Initialize any players added before connecting to PlayerAdded event
for _, player in Players:GetPlayers() do
  onPlayerAdded(player)
end

local function onPlayerRemoved(player)
  updatePlayerCoins(player, function(_)
    return nil
  end)
end

Players.PlayerAdded:Connect(onPlayerAdded)
Players.PlayerRemoving:Connect(onPlayerRemoved)

Code Explanation

The code defines functions to reset coin counts during the appropriate lifecycle events:

Player.PlayerAdded fires when a player joins the experience, and sets the coin count to 0.
Player.CharacterAdded fires when a player's character model is added to the world. It occurs after PlayerAdded and whenever the player respawns.
Humanoid.Died fires when a player dies, and sets the coin count to 0. task.spawn() creates a separate thread for handling this, so other aspects of the player life cycle can execute.
Player.PlayerRemoved fires when a player leaves the experience to clean up player state.
This code contains a potential issue where players could collect coins before the Players.PlayerAdded event executes and then have their coin counts reset to zero. To mitigate this issue, consider solutions such as code scheduling or freezing the player's character until initialization finishes. However, these solutions involve more complex scripting concepts that are beyond the scope of this tutorial.

Playtest

It's time to see if the player hazard works as intended. When you touch the water, your character should die and lose their coins. To test your game:

In the menu bar, click the Play button. Studio enters playtest mode.
Move your character to collect some coins, then jump in the water. If your scripts are working correctly, your character dies, and the coin count on the leaderboard resets to 0.