Question

if someone says 'duh!!' what does it mean are they saying it in a friendly manner or to have a war?​

Answer 1

It may differ in various situation and context.

Hope it helps you

Answer 2

it honestly depends on the context or sentence they are using it in. But to me 'duh' would be used to point something obvious out- so it can be used in an attacking way.

Hope this helps  :  )