What are you able to put inside of the () other than getchildren or tables? Anything specific?
for ex this script would kill all the players. inside the pairs parameter you would insert a table, and v would be representing all the members of that table. So right now, v is representing all of the instances under the property of 'Players' Hope this helps!
for i,v in pairs(game.Players:GetChildren()) do v.Character.Humanoid:TakeDamage(100) end