Raycast, Region, or Cast: What’s the Best Choice for Melee Combat in Roblox?

Every new developer has probably asked themselves: what’s the best way to detect melee hits?
Some even default to the classic .Touched() — but have you ever heard of DOT?

The Dot Product is one of the most underused tools in Roblox melee systems. And let’s be clear: it’s made for close combat.

While Raycasts and Region checks work, they can become too heavy when triggered repeatedly at high speed. When milliseconds matter, you want something that’s instant, cheap, and accurate — and that’s exactly where the Dot Product shines.

The logic behind this operation is fairly straightforward — but like any tool, it comes with trade-offs.

For starters, there’s no built-in obstruction check. That means you might accidentally register hits through walls or solid objects if you’re not careful.

Depending on how it’s implemented, it can also lead to performance issues, especially if you’re looping too often or handling too many targets at once.

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To work around these limitations, developers usually:

• Set a tight detection range
• Add invalidation layers, like checking if the sword collides with geometry before applying the hit

✅ Pros:

• Easy to implement and expand
• Lighter than Raycasts in most cases

Perfeito, Thiago. Aqui está uma versão formatada do seu conteúdo para Medium, misturando explicação técnica, boas práticas e o seu código real com comentários e seções divididas de forma clara:

Step-by-Step Logic

1. Start the Function

We define a function that receives the Player and a numeric Range, and returns the closest aligned character.

return function(Player, Range)
	local CloseObjects = {}

2. Loop Through All Characters

Assuming we store all active, living characters in a workspace.Lives folder, we loop through them:

for _, _Character in workspace.Lives:GetChildren() do

We ignore the player’s own character and apply three checks:

• The character isn’t the player
• It has a HumanoidRootPart
• It’s within the defined distance

if _Character ~= Player.Character 
			and _Character:FindFirstChild("HumanoidRootPart") 
			and Player:DistanceFromCharacter(_Character.HumanoidRootPart.Position) < Range then

3. Calculate the Dot Product

This is the key step: we check if the character is in the player’s field of view.

local Dot = ((_Character.HumanoidRootPart.Position - Player.Character.HumanoidRootPart.Position).Unit)
				:Dot(Player.Character.HumanoidRootPart.CFrame.LookVector)

🔹 What is this doing?

• We subtract the target’s position from the player’s position.
• We apply .Unit to normalize the direction vector (magnitude becomes 1).
• We use .Dot() to measure alignment with the player's LookVector (where they're looking).

Dot values:

• 1 → perfectly in front
• 0 → sideways
• < 0 → behind

4. Filter Based on Vision Cone

We keep only characters that are in front of the player — not too far off to the side.

if Dot < 1 and Dot > .6 then
  table.insert(CloseObjects, {_Character, Player:DistanceFromCharacter(_Character.HumanoidRootPart.Position), Dot})
end

This means only characters that are within a cone in front of the player are considered.

5. Sort by Alignment

Once we gather all visible characters, we sort them by Dot (alignment) to get the one most centered in view.

table.sort(CloseObjects, function(OBA, OBB)
      if not OBA[3] or not OBB[3] then
	 return OBA[3] or OBB[3]
       end

       return OBA[3] > OBB[3]
end)

6. Return the Best Match

We return the character most aligned to the center of the screen (i.e., highest Dot).

return CloseObjects[1] and CloseObjects[1][1]
end

Personally, I use Dot for simpler hitboxes like melee combat, where I need quick, lag-free responses. This allows me to create a more fluid and organized environment without relying on complex operations.

Well, thanks for reading.