There will be opening theory soon, and it will be essential in many cases.
For instance after 1.e3 e6 2.Qh5, White threatens Qxf7+ which would force black to play the top engine move. Then 2...g6 3.Qxg6 is one idea -- but there are two recaptures, fxg6 and hxg6, and only one of them can be the top engine move (hxg6, I'm guessing). So 3...fxg6 probably refutes this idea. But are you sure enough as white to try to claim a win if black goes hxg6?
And after say 1.e3 e6 2.Qh5 g6 3.Qxh7 (avoiding that line and going for material), not only does black not have to care about their rook (white can't take it, it would be the best move), black actually has 3...Qh4 winning -- he threatens 4...Qxf2+, white can't play 4.Qxh4 as that's the best engine move, and white's queen is threatened twice, so black will be able to take it -- provided he checked this line before the game to know which piece to take with.
Edit: it doesn't actually win, white has 4.Qf5 to defend f2... what a strange game.
Edit 2: once a piece is _en prise_ somewhere, the game can otherwise become somewhat normal as taking it would be the best move and so would moving it to a safe spot - so other moves can be played as usual. But would they be good?
For instance after 1.e3 e6 2.Qh5, White threatens Qxf7+ which would force black to play the top engine move. Then 2...g6 3.Qxg6 is one idea -- but there are two recaptures, fxg6 and hxg6, and only one of them can be the top engine move (hxg6, I'm guessing). So 3...fxg6 probably refutes this idea. But are you sure enough as white to try to claim a win if black goes hxg6?
And after say 1.e3 e6 2.Qh5 g6 3.Qxh7 (avoiding that line and going for material), not only does black not have to care about their rook (white can't take it, it would be the best move), black actually has 3...Qh4 winning -- he threatens 4...Qxf2+, white can't play 4.Qxh4 as that's the best engine move, and white's queen is threatened twice, so black will be able to take it -- provided he checked this line before the game to know which piece to take with.
Edit: it doesn't actually win, white has 4.Qf5 to defend f2... what a strange game.
Edit 2: once a piece is _en prise_ somewhere, the game can otherwise become somewhat normal as taking it would be the best move and so would moving it to a safe spot - so other moves can be played as usual. But would they be good?