Onslaught

Large variants are often slow, because the slow pieces start in defensive positions, so that the defender has the advantage as long as the attacker has not brought his own slow pieces to the attack. In Onslaught this situation is reversed, by using modified versions of the common leapers: Knight, Camel, Zebra, Elephant and Champion.

This modification, for which we coin the general term 'flash leaper', replaces some or all of the moves of the piece by the non-capturing rider move with that same leap when the piece starts its move from its own board half. This makes these pieces useless (or in any case much weaker) as defenders, which again makes the attacking power of the armies larger than their defensive power. The rider move makes it possible to bring those pieces to the attack in a single move.

Setup

Pieces

The King Queen, Rook, Bishop Knight and Pawn move as in orthodox Chess, possibly except for a difference stated below. Unless explicitly stated otherwise, pieces capture as they move.

The King moves 4 steps on castling. None of the squares passed through must be under attack.

Pawns can slide forward to any empty square on their own board half, even when they have moved already (as in Wildebeest Chess). They can then be taken en passant by Pawns on adjacent files on any square they passed through.

The Knight cannot capture when standing on its own board half, but can move (without capturing) like a Nightrider instead (i.e. multiple Knight jumps in the same direction as long as the involved squares are empty)

A Marshall moves like an orthodox Knight or Rook.

An Archbishop moves like an orthodox Knight or Bishop.

A Griffon moves by leaping like a Knight, and from there slides orthogonally outward like a Rook. Note it cannot move one step diagonally, nor does it care what is on that square. (Some would call this a Ski-Griffon.)

The Rhino moves by leaping like a Knight, and from there slides diagonally outward like a Bishop. Note it cannot move one step orthogonally, nor does it care what is on that square. (This is the Unicorno from Grant Acedrex.)

A Champion moves and captures one step orthogonally, or by jumping to the second square orthogonally. On the enemy board half it can also move and capture by jumping to the second square diagonally. (This makes it the normal Champion fom Omega Chess.) On its own board half, instead of this latter move, it can make one or more jumps in the same direction, each spanning two diagonal steps, as long as the visited squares are empty (i.e. as an Alfilrider).

An Elephant moves and captures one step diagonally. From the enemy board half it can also jump to the second square diagonally to move or capture. From its own board half, instead of this latter move, it can make one or more jumps in the same direction, each spanning two diagonal steps, without capturing (i.e. as an Alfilrider).

A Camel makes a (3,1) leap. From its own board half it cannot capture, but instead repeat the leap in the same direction as long as the visited squares are empty.

A Zebra makes a (3,2) leap. From its own board half it cannot capture, but instead repeat the leap in the same direction as long as the visited squares are empty.

Rules

Pawns promote upon reaching the furthest rank, to Queen, Marshall, Archbishop, Griffin or Rhino.

The loss of their capture moves on their own board half does not include the power to deliver check: Knight, Camel, Zebra and Elephant can check the King from anywhere with the capture moves they would have in enemy territory.

Where not explicitly contradicted, FIDE rules apply.

Notes

The Elephant retains some of its captures on its own half, and thus is the only low-value defensive piece. The Champion also does that, but with 12 move targets instead of 8 is worth much more. A Bishop is also worth significantly more than an 8-target leaper on 12x12. Defense against the attacking leapers thus must mostly come from the Pawns. Hence the double rank of those that you could use as King shelter. Such a double rank can be attacked at the base with the range-3 leapers (C and Z), though, where the Pawns can only be protected by high-valued pieces.

Since the range-3 leapers can attack the 2nd rank from beyond initial Pawn range, most pieces there in the initial position are also low value, so that there is nothing for them to gain there. The exceptions, Griffon and Rhino, cannot be forked by these leapers, and due to their jumping moves can easily move away when attacked.

The initial setup is inversion-symmetric rather than reflection symmetric, to encourage opposit castling, and Pawn storms.

My thanks go to A.M. DeWitt for helpful suggestions for the rules and setup.

Last revised by H. G. Muller.