Drop variants of Chess were invented and implemented for example, by Andreas Kaufman (Descent Chess 2003, all pieces has to be dropped except for Kings and 2 pawns), by Gm.Yasser Seirawan (added 2 dropped extra pieces Hawk and Elephant for standart chess setup) in 2007, by Mats Winther (Alternative Chess added 2 pawns) and many others. The Classical Carrera pieces was known already in the 17th century. Carrera is also remembered as the inventor of chess variant (Carrera's chess) on an 8x10 chessboard, in which there were added two new pieces called the Champion (a combination of the moves of the tower/rook and the knight) and Centaurus (a combination of the bishop and the knight); these innovations had more fame than the ones made by Piacenza and Marinelli. It was a predecessor of Capablanca chess.Hence,the Universal chess is variation (or hybrid) of Gm.Yasser Seirawan, Andreas Kaufman and Mats Winther (invented 2 extra pawns chess where are 2 extra pawns has to be dropped in second row and a pawn has to be move 2 steps ahead immediately) chesses with some extra new rules. Capablanca chess for board 10x10 with 2 extra pieces was proposed by J.R.Capablanca.

In this zrf.file:

I-Two extra pieces you can drop any free square in the last rank in any time but, it is to be considered as one move.

II-Two extra pawns/peons can to drop on the free second row, it is to be considered as one move and dropped pawns has to be promote only to Classical chess pieces (not to extra dropped pieces).

In this situation all of a great heritage classical chess will be unchanged.
Also here introduced - The Invisible Man, Clash of the Civilization Chess and Amazons chess.