Dead on

I love vernacular.. It offers insights into people and culture. This poster places an iconic sketch of tayto crisps and the ulster vernacular expression 'dead on'
Depending on how its said, inflected... it can mean "that's great", "alright", "perfect" .
How was the meal?" "Dead on?"
"What's jonny like" "Aw he's a dead on fella.
or negatively "no chance".....
"Come with me? Aye, dead on!" Ie no chance!
Variety is great.