The Game of Nemoroth

Scriven By Ralph Betza

The City of Nemoroth

The rules they used were not the rules we know, for Nemoroth thrived when the world was still being built -- indeed, it was in the harbor of Nemoroth that the Moon was made, and the city destroyed by accident when Luna was floated up into the sky.

In Nemoroth, one did not play chess with crude figurines of plastic or wood; instead, the actual creatures were moved about on a vast playing field suspended in the unfinished firmament.

The Basilisk

Any piece which is seen by a Basilisk, be it friend or foe, is instantly thrown into a paroxysm of torment and petrified.

Petrified pieces continue to see and continue to suffer their torments, as evidenced by the dim glow of fire that can be discerned deep within their malachite forms.

The Ghast

The Ghast moves by jumping two squares diagonally, and must land on an empty square.

Flight

Compelled Moves

If multiple pieces are compelled, the player may choose any of them.

If some pieces are compelled, but none have legal moves, the game is lost.

Sometimes it is possible to make a saving move with some other piece than the compelled one. For example, suppose that your Basilisk has been pushed onto an occupied square, and so is compelled to move off, but has no legal move; if you can engulf your own Basilisk with a leaf pile, you have removed the condition causing the compulsion, and therefore you have saved the game.

The Leaf Pile

However, this pile of leaves is animated, animated by a spirit so evil and so ancient that there are no words to describe either its malignance nor its anciency.

The Leaf Pile moves one square in any direction, and if the square to which it moves or is moved is occupied, it engulfs every occupant of that square, friend or foe; and when it moves on after engulfing, it leaves a single hideous mummy of such terrifying aspect that no other piece will ever voluntarily occupy the same square as the mummy.

There are still leaf piles on Earth, but whether any are animated is a question no one dares investigate; after all, a piece that is moved onto a Leaf Pile is engulfed and mummified...

The Go Away

Instead of moving, it can stay in place and make every adjacent piece, whether friend or foe, flee one square straight away from it. (see the Interactions section for details)

A colony of Go Aways still survives, on Saturn.

The Wounded Fiend

The Wounded Fiend was given its painful wound by a magical sword, and the wound continues at all times to ooze copious amounts of fetid ichor which drench every square it lands on or crosses. No piece, neither friend nor foe, will dare venture upon an an ichorous square until the ichor evaporates five moves later.

So many games were played in Nemoroth, and so many Wounded Fiends were pushed off the board to fall forever, that the tracks of ichor left by the falling Fiends can be seen even now in the sky. In our ignorance, we call it the Milky Way.

The Human

Upon reaching the eighth rank, a Human becomes a Zombie.

In Nemoroth, the pieces now called Humans had a different name; but that was so long ago that the name for that piece, and even the creature it was named for, are now forgotten.

The Zombie

Ichor destroys Zombies. A Zombie which is involuntarily moved to an ichorous square is dissolved.

Winning the Game

Merely by playing it, you have consigned your spirit to the nether depths where all the unspeakable horrors dreamed of by the Elder Gods will be visited upon you!

Ah, but if you insist on playing, at least try to deprive your opponent of all legal moves. He who has no moves loses in all senses, while the other player at least manages to feel the taste of an evanescent and hollow victory.

Shudder

What eldritch noise did I hear?

Official Rules of Nemoroth

This section attempts to list them all and to specify all elements and interactions precisely and clearly.

General Inventory

There are 3 victory conditions: simple stalemate, stalemate by compulsion, and stalemate by repetition.

There are 7 types of mobile pieces including the Zombie; there are 5 distinguishable types of petrified piece, and one type of mummy, for a total of 6 types of immobile piece; in addition there are 6 types of squares: empty squares, ichorous squares, Ghastly squares (friend and foe), squares seen by Basilisks, and multiple occupancy squares.

Victory Conditions

It is forbidden to repeat a position, and so one can win by zugszwang. A position is considered to have been repeated when all conditions are the same: the same player must be on the move, all the mobile pieces must be in the same places, the same number of mummies and of statues must be in the same places, and the amount of ichor on all squares must be the same.

Digression: Repetition and Stalemate

Nimzovich would approve of this proposition. Victory by Zugzwang!

When a chess variant author specifies victory by stalemate, it should be assumed that repetition of position is forbidden.

somebody should really write a file called "Rule Zero for Chess Variants", and one of the rules should be:

"When a chess variant author specifies victory by stalemate, it should be assumed that repetition of position is forbidden."

Victory Conditions Continued -- return from Digression

The details of compulsion can be complex, and cannot be discussed without referring to the specific powers of the pieces; and so, discussion of the details is deferred until later in the document.

Mobile Pieces

Mobile Piece Type: Basilisk

Moves as ffNbF, but only to empty non-ichorous squares.

The Knight move is a leap, and therefore is not hindered by obstacles of any sort.

Any piece, friend or foe, on a square to which a Basilisk could move, is petrified; the squares the Basilisk can move to are the squares it can see.

Tactically, the fact that the squares a Basilisk sees are the same as the squares to which it can move means that the Basilisk can effectively stalemate itself.

A Basilisk which finds itself on a multiple occupancy square or on an ichorous square is compelled to move off. A Basilisk which finds itself within range of an enemy Ghast is compelled to flee, and may not approach a Ghast of either allegiance.

Square Type: Basilisk Square

Petrification is immediate, and is both active and passive: petrification occurs when a Basilisk moves and sees a piece, it occurs when a piece moves onto a square seen by a Basilisk, it occurs when a Basilisk is pushed by a Go Away and sees a piece from its new square, and it occurs when a piece is pushed onto a square seen by a Basilisk.

Zombies cannot be petrified.

Riders cannot cross squares seen by Basilisks, but leaping pieces can.

The only Rider in the game is the Wounded Fiend. If it tries to cross a square seen by a Basilisk, its move ends and it is petrified.

The only leaping pieces are the Ghast, the Go Away, and the Basilisk itself. They can cross a square seen by a Basilisk because their talons never touch the ground.

Immobile pieces are not affected by the Basilisk. Statues are already petrified and mummies cannot be petrified.

The gaze of a Basilisk does not affect ichor: a basilisk square may also be an ichorous square.

Immobile Piece Type: Petrified Basilisk

Mummifying a petrified Basilisk stops it from seeing.

In addition to the above special considerations, the Petrified Basilisk also follows the same rules as all other petrified pieces.

Rules Common to All Types of Petrified Pieces

All petrified pieces can be mummified, but this can only happen by pushing a Leaf Pile (or a petrified Leaf Pile) onto the square containing the statue.

Petrified pieces are not compelled to flee a Ghast, and they are not compelled to move off a square that has multiple occupants.

Petrified pieces are already petrified, so the gaze of a Basilisk has no effect on them.

Statues are not affected by ichor.

Basilisk Tactics

With Alabaster Basilisk e5 and Obsidian Basilisk e4, retreating from e5 to f4 is very strong.

An early Basilisk attack should be met by a Leaf Pile counterattack.

Advancing Humans in order to petrify them where they clog up enemy development is a very valid tactic.

Mobile Piece Type: Ghast

The Ghast is a leaping piece, so it can leap over occupied squares or ichorous squares or Ghast squares or Basilisk squares with no harm done.

The Ghast causes flight within a range of two squares. For example, a Ghast on e4 would cause flight everywhere within the square of squares whose corners are c2, c6, g6, and g2.

A Ghast which finds itself on a multiple occupancy square or on an ichorous square is compelled to move off.

Square Type: Ghast Square

To flee means that the piece must end its move geometrically further away from the Ghast than it was when it started its move; for example, if your Ghast is on b3, you can move your Human from b2 to c2 because the geometrical distance between the two pieces has increased.

Mobile pieces within the range of an allied Ghast are not compelled to move, but when they do move they must flee. In other words, your own Ghast restricts the movements of your own pieces.

Mobile pieces within the range of an enemy Ghast are compelled to flee; but remember that a saving move can be made by some piece other than the compelled piece -- for example, petrifying a piece removes its compulsion.

The Zombie is immune to the effects of the Ghast.

Compulsion is covered thoroughly later on, in the section "Details of Compulsion".

A petrified Ghast still causes flight, but a mummified Ghast does not.

Ghasts are affected by Ghast squares: they may not approach each other, and if they are pushed together one of them is compelled to flee.

Immobile Piece Type: Petrified Ghast

Otherwise, see the Common Rules for Petrified Pieces.

Mobile Piece Type: Leaf Pile

The Leaf Pile cannot move of its own accord onto an ichorous square, nor onto a square containing a statue, nor onto a square containing a mummy. However, it can move onto a square which contains multiple pieces, but only if none of them are statues or mummies and there is no ichor on the square.

When the Leaf Pile moves onto an occupied square, or when it is pushed onto an occupied square, it engulfs all the pieces on that square, both the mobile and the immobile pieces, and whether they are friend or foe.

When a piece other than a Leaf Pile is pushed onto the same square as a Leaf Pile, it is engulfed by the Leaf Pile.

When a Leaf Pile moves or is pushed onto a square containing another Leaf Pile, the moving piece engulfs the stationary one.

A Leaf Pile is subject to the effects of a Basilisk.

Zombies are not immune to being engulfed.

A Leaf Pile is subject to the effects of a Ghast; however, if it is adjacent to an enemy Ghast it can make a saving move by engulfing the Ghast (this is not considered approaching the Ghast because the Ghast is engulfed!).

A Leaf Pile which finds itself on an ichorous square is compelled to move off. A Leaf Pile does not engulf ichor.

A Leaf Pile finding itself on a multiple occupancy square would be compelled to move off, and not permitted to engulf without moving; however, this cannot happen!

When a Leaf Pile makes its first voluntary move after engulfing something, it leaves behind a single Mummy; notice that this means no Mummy is left behind when a Leaf Pile that is digesting something is pushed; the Mummy is, as always, left behind when the Leaf Pile moves on of its own accord.

A statue can be turned into a Mummy, but this can only be done by pushing a Leaf Pile onto the same square as the statue or by pushing the statue onto the same square as the Leaf Pile.

Immobile Piece Type: Petrified Leaf Pile

Otherwise its rules are the same as any statue.

Notice that pushing a petrified Leaf Pile does not leave behind a Mummy, even if the Leaf Pile has eaten something.

Immobile Piece Type: Mummy

Mummies cannot be petrified, they cannot be compelled to flee, and they cannot be compelled to move off an occupied square.

Mummies are not affected by ichor.

A Mummy can be destroyed by a Zombie, pushed by a Go Away, or engulfed by a Leaf Pile (but a Mummy can only be engulfed when either it or the Leaf Pile is pushed).

All mummies are the same. No matter what the piece started the game as, once it becomes a Mummy it is totally inert.

When a Leaf Pile engulfs things, there is nothing on the square but the Leaf Pile itself; the Mummy is not generated until the Leaf Pile moves on.

Mobile Piece Type: Go Away

Instead of moving, it can scream GO AWAY! and all adjacent pieces, whether friend or foe, whether mobile or immobile, are pushed one square directly away from it. A Go Away may not scream if there are no adjacent pieces.

The owner of the Go Away chooses the order in which the pushing is done, but this is only important when a Basilisk is involved. For example, imagine an Obsidian Leaf Pile on d5, an Obsidian Go Away on e5, an Alabaster Leaf Pile on f5, and an Obsidian Basilisk on e6: Black to play has his Go Away scream GO AWAY!, and first pushes the Leaf Pile from d5 to safety on c5, then pushes the Basilisk from e6 to e7, petrifying the Leaf Pile on f5, and then pushes the statue from f5 to g5.

The Go Away can push pieces off the edge of the board, in which case they are completely gone from the game.

By pushing a Basilisk, or by pushing a Petrified Basilisk, the Go Away can cause more pieces to be petrified.

By pushing a Ghast, a Go Away can cause a compulsion to flee.

By pushing a Leaf Pile, a Go Away can cause engulfment.

By pushing statues or mummies, a Go Away can break up a solid blockading wall.

Pushing a Human can promote it.

A Go Away can destroy a Zombie by pushing it onto an ichorous square. Other mobile pieces that are pushed onto ichorous squares are compelled to move off.

Tactically, the Go Away has the richest possibilities, and often delivers the decisive stroke.

The Go Away can be petrified, and a petrified Go Away is mute.

The Go Away cannot approach a Ghast, and may be compelled to flee an enemy Ghast (but pushing the Ghast further away counts as flight).

A Go Away which finds itself on an ichorous square or on a multiple occupancy square is compelled to move off. ("The same square" is not "an adjacent square", so the Go Away cannot push itself by screaming.)

A Go Away can be pushed by another Go Away, it can be engulfed by a Leaf Pile, it can be destroyed by a Zombie.

Screaming does not move ichor.

The Go Away can push pieces onto occupied squares, which creates a Multiple Occupancy Square.

Square Type: Multiple Occupancy Square

If a Zombie is pushed onto an occupied square, it is compelled to move off without destroying the other occupants of the square.

Mobile Piece Type: Wounded Fiend

The Wounded Fiend is the only rider in the game. Because it moves along the ground, it cannot cross a Basilisk Square -- instead, it gets petrified and its movement stops there.

Whenever a Wounded Fiend moves off a square, and whenever it is pushed off a square, it leaves behind fetid ichor, which takes five moves to evaporate. This is called an "ichorous square".

Because it is a rider, it leaves each square it crosses; thus in moving from a1 to a8 it would ichorify the squares a1 through a7.

The square it lands on is not ichorated, because the ichor is deposited only when the Wounded Fiend leaves a square.

The Wounded Fiend can be petrified by a Basilisk or by a petrified Basilisk, engulfed by a Leaf Pile or Petrified Leaf Pile, compelled to flee by a Ghast or by a Petrified Ghast, pushed by a Go Away, or destroyed by a Zombie.

A Wounded Fiend that finds itself on an ichorous square or on a multiple occupancy square is compelled to move off.

Square Type: Ichorous Square

If pushed onto an ichorous square, a mobile piece other than Zombie is compelled to move off. Exception: if the ichor will evaporate after you make your move but before your opponent moves, you can ignore it.

Ichor destroys Zombies and Zombies destroy ichor. If a Zombie moves itself onto an ichorous square, the Zombie is destroyed and so is the ichor, along with any creatures or mummies or statues that were on the square.

If a Zombie is pushed onto an occupied ichorous square, the occupants are unharmed but the ichor and the Zombie are both destroyed.

Immobile Piece Type: Petrified Wounded Fiend

Otherwise it behaves as any statue.

Azgoroth's Simple Puzzle

Does the Wounded Fiend stalemate itself? Azgoroth required you to answer without moving the pieces around, or forfeit your wager.

After 1. a1-a8, the squares a1 to a7 are ichorous, and so the Fiend has no choice but to continue 2. a8-h8, and onwards to h1 and b1 and then to b7 and g7; and when the move 6. b7-g7 was made, had the ichor evaporated yet? If g7 was chosen only because it was longest, then the Fiend will not stalemate itself; instead, there will come a moment when its longest move takes it back out to the edge of the board. But if instead the move 6. b7-g7 was made both because it was the longest and because a7 was still ichorous, then the Fiend must eventually stalemate itself.

A simple puzzle, and yet Azgoroth won vast sums with it.

Before playing 6. b7-g7, a7 is ichorous. After making the move, but before the opponent's move (if there had been an opponent in this puzzle), the ichor on a7 (and on a1, a2, a3, a4, a5, and a6) finishes evaporating and is completely gone. It is stalemate, and "The Wounded Fiend carries within it the seeds of its own destruction", as Azgoroth said of this puzzle.

Mobile Piece Type: Human

The Human can be petrified, mummified, compelled to flee, compelled to move off, engulfed, pushed, or destroyed. It has no offensive power and is immune to nothing.

The Human can get in the way of other pieces, and if it ever reaches its eighth rank its reward is to be transformed into a Zombie.

Who would choose to be a Human?

If a Human that is compelled to flee a Ghast can advance to its eighth rank and thus promote to a fearless Zombie, it does not matter whether the move is a geometrical flight; by promoting, it removes its compulsion to flee and thus is saved.

Mobile Piece Type: Zombie

The Zombie moves one square in any direction, even to occupied squares or ichorous squares. It destroys everything on the square.

Zombies cannot be petrified and they cannot be compelled to flee.

Zombies can be engulfed, or pushed, or destroyed by other Zombies.

If a Zombie is pushed onto an occupied square, it is compelled to move off without destroying the other occupants of the square.

Ichor dissolves Zombies and Zombies destroy ichor. If a Zombie moves itself onto an ichorous square, the Zombie is destroyed and so is the ichor, along with any creatures or mummies or statues that were on the square.

If a Zombie is pushed onto an occupied ichorous square, the occupants are unharmed but the ichor and the Zombie are both destroyed.

Details of Compulsion

If you have compelled pieces, your moves are restricted, much like being in check. However, compulsion can be more powerful than check because if you have several compelled pieces the opponent has several moves of free action (can go around engulfing everything while you are helpless).

If you have any compelled pieces, you must usually move one of them as your move, although you may choose among your compelled pieces with legal moves. If you have compelled pieces, and none of your compelled pieces have legal moves (unless there is a saving move), you are stalemated and thus lose.

If you have compelled pieces, sometimes you can move a non-compelled piece in a manner that the side-effects of your move remove the compulsion. For example, if you have several pieces compelled to flee from the enemy Ghast, but you have a Zombie next to the enemy Ghast, you can move the Zombie onto the enemy Ghast, thus destroying it, and also thus saving your compelled pieces from their compulsions. This is called a "saving move".

Another example of a saving move: suppose your Basilisk is on the same square as a Mummy; it is compelled to move off. However, if you can engulf your own Basilisk with a Leaf Pile (by pushing the Leaf Pile onto the same square as the Basilisk), the Basilisk is no longer compelled to move off because it no longer exists. In order to save the Basilisk, you had to destroy it; that's the way it goes in Nemoroth.

Consider the gamelet 1. Be1-d3 (petrify e2 and c2), Gd8-b6 2. Bd3-e5? (petrify d7 and f7), Gb6-d4! (petrify d4).

Has Alabaster lost the game? A petrified Ghast still compels flight and therefore the pieces at b2, d2, f2, and e5 are all compelled to flee. The statues at e2 and at c2 are not compelled.

The Human at b2 can flee to a3, and the Basilisk at e5 can flee to f4 (because although it's still within range of the petrified Ghast, at least it's further away) and then to either g6 or to g3 (which petrifies the Human on f2 and removes its compulsion), and the Human at f2 can either flee to g3 or it can wait for the Basilisk to petrify it.

These moves can be played in any order, but at the end of it all, The Human at d2 has no place to run. Engulfing it with Lc1:d2 is not legal because in order to make this move the Leaf Pile would need to approach the Ghast; and the fact that it's a saving move doesn't make it a legal move. White is checkmated.

These moves must be played one at a time, and the opponent gets to move in normal sequence. Therefore, when you have several pieces compelled at once, you are at a huge disadvantage; the opponent will take advantage of you by engulfing things while you can't respond, or by putting even more of your pieces into compulsion, or by committing other horrible and atrocious deeds.

These moves must all be legal moves according to the normal rules. Being compelled to move doesn't allow you to move onto ichor or to approach a Ghast and so on.

Hypothetically, if Alabaster had a Go Away at c1 (instead of the Leaf Pile which is there), it could first flee with Be5-f4 and then command its Go Away at c1 to scream, thus pushing b1 to a1, b2 to a3 (this is a "saving move" because the Human which was at b2 is now beyond the Ghast's range of influence), c2 to c3, d2 to e3 (the Basilisk petrifies it, so this is also a saving move), and d1 to e1. Although this move has added one compulsion (there are two pieces on a1, and one must move off), the count is unimportant. As long as the move is a legal move and also includes at least one "saving move", it can be played. In this hypothetical situation, Alabaster could continue to fight (but the petrified Ghast at d4 would cripple Alabaster's game).

This is complicated, but it's the correct way. I hope that it's enough of an example to allow complete and correct understanding.

At the moment, I cannot write a set of formal rules in formal format that clearly and completely covers all the points that the example illustrates.

References

The game of Ultimate Ultima, a collaboration between this author and John Ishkanian, was three orders of magnitude more complex than the Game of Nemoroth.

The city of Lankhmar (created by the Class A chessplayer and Grandmaster writer Fritz Lieber) could exist in the same universe as Nemoroth, but Nemoroth would come many aeons before Lankhmar in its chronology.

I have recently commented about some games being good games but not chess variants. Do you agree that the Game of Nemoroth is a chess variant although it pushes and stretches the limits?

Credits

In alphabetical order, I can find Peter Aronson, Ben Good, David Howe, John Lawson, Moussambani, plus of course Hans, without whom none of this would have happened.