The short answer is: A game very much like chess where two new pieces are added to the game to make it more interesting.

A slightly longer answer: An 80-square version of chess that features a new piece that can move like a Knight or Rook, and another new piece that moves like a Knight or a Bishop. The Chancellor is the name of the Knight + Rook piece, and the Archbishop is the Knight + Bishop piece.

"New" may not be the precise word to describe these pieces. If this is the first time you have heard about them, then, yes, it is "new to you" as far as you are concerned. But the idea of using such pieces goes back as least as far as Pietro Carrera in the year 1617 A.D. While he used different names than I have shown here, his "Alfincavallo" moved like an Archbishop and his "Roccocavallo" moved like a Chancellor.

In 1874, Henry Bird experimented with an 80-square arrangement of his own. He put his pieces on different squares than Carrera's. Later on, in 1924, World Champion Jose Capablanca came up with a setup of his own, different from both of his predecessors. While it is true that I first heard of an 80-square variant when I encountered a description of Capablanca's Chess, it is not true that Trice's Chess is derived from that game. Trice's Chess more closely resembles the setup of Henry Bird than either Capablanca's Chess or Carrera's Chess. If you interchange the location of the Queen and Chancellor in Trice's Chess, you have Henry Bird's configuration.

Trice's Chess is arranged in such a way that all pawns are protected by at least one piece at the start of the game. None of the other 10x8 chess variants using these pieces can make this claim. This is why Trice's Chess is preferred over Capablanca's Chess and Bird's Chess and Carrera's Chess. The bold, attacking player will tend to like Trice's Chess more than regular 8x8 chess.