Against 1.e4, right away
Scandinavian and Petrov: hitting the centre on move one, with no preparation at all.
The defences in the last module (Sicilian, French, Caro-Kann) prepare their counter-punch in the centre. The two here do not prepare: they hit e4 immediately. The upside is having nothing to memorise; the price is that White gains time attacking what you pushed forward.
The Scandinavian. Black trades in the centre on move one and brings the queen out early.
The Petrov. Instead of defending the e5 pawn, Black attacks the e4 one.
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