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Overview

The Mouse and Cats game can be customized in several ways without changing the core rule logic. This guide shows you how to modify visual elements, piece symbols, and game parameters.

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Modifying Piece Symbols

Piece symbols are defined using the pieza template in the initial facts section.

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Current Piece Definitions

See: raton_y_gatos.clp:128-157 White Square (valor 0): 
(pieza
  (valor 0)
  (parte1 "       ")
  (parte2 "       ")
  (parte3 "       ")
)
Black Square (valor 1): 
(pieza
  (valor 1)
  (parte1 " . . . ")
  (parte2 " . . . ")
  (parte3 " . . . ")
)
Mouse (valor 4): 
(pieza
  (valor 4)
  (parte1 "(_)_(_)")
  (parte2 " (o o) ")
  (parte3 "==\\o/==")
)
Cat (valor 5): 
(pieza
  (valor 5)
  (parte1 " /\\_/\\ ")
  (parte2 "( o.o )")
  (parte3 " > ^ < ")
)

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Customizing Piece Appearance

1

Open the source file

Open ~/workspace/source/raton_y_gatos.clp in a text editor.
2

Locate the pieza definitions

Find the deffacts hechos-iniciales section (around line 110).
3

Modify the ASCII art

Each piece has exactly 7 characters per part (to fit the board grid). Maintain this width:
(pieza
  (valor 4)
  (parte1 " <(o)> ")  ; Custom mouse design
  (parte2 "  \\ /  ")
  (parte3 "  =M=  ")
)
4

Test your changes

Load the file in CLIPS:
CLIPS> (load "raton_y_gatos.clp")
CLIPS> (jugar)
Each parte string must be exactly 7 characters wide. If you use fewer characters, add spaces. If your design is too wide, it will break the board alignment.

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Alternative Piece Designs

Minimalist Style: 
; Mouse
(pieza (valor 4) (parte1 "       ") (parte2 "   M   ") (parte3 "       "))

; Cat
(pieza (valor 5) (parte1 "       ") (parte2 "   C   ") (parte3 "       "))
Unicode Style: 
; Mouse (using Unicode if your terminal supports it)
(pieza (valor 4) (parte1 "       ") (parte2 "   🐭   ") (parte3 "       "))

; Cat
(pieza (valor 5) (parte1 "       ") (parte2 "   🐱   ") (parte3 "       "))
Unicode symbols may not render correctly in all CLIPS terminals. Test before committing to this style.

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Adjusting Initial Positions

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Default Starting Position

The initial piece placement is defined in the posiciones-piezas-iniciales rule (lines 209-259). Current setup:
  • Mouse: Row 1, Column 4
  • Cat 1: Row 8, Column 1
  • Cat 2: Row 8, Column 3
  • Cat 3: Row 8, Column 5
  • Cat 4: Row 8, Column 7
See: raton_y_gatos.clp:234-255

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Changing Starting Positions

1

Locate the positioning rule

Find defrule posiciones-piezas-iniciales around line 209.
2

Modify the mouse position

Change the row and column in the pattern match:
; Original
?raton <- (casilla (fila 1)(columna 4)(valor ?))

; Modified - start mouse at column 2
?raton <- (casilla (fila 1)(columna 2)(valor ?))
3

Modify cat positions

Change any cat’s starting row/column:
; Original cats in row 8
?gato1 <- (casilla (fila 8)(columna 1)(valor ?))
?gato2 <- (casilla (fila 8)(columna 3)(valor ?))

; Modified - cats start closer (row 6)
?gato1 <- (casilla (fila 6)(columna 1)(valor ?))
?gato2 <- (casilla (fila 6)(columna 3)(valor ?))
4

Update the modifications

The modify statements must match your new pattern:
(modify ?raton (valor 4))
(modify ?gato1 (valor 5 1))
Initial positions must be on black squares (odd row + odd column OR even row + even column). Placing pieces on white squares will break game logic.Valid positions:
  • (1,1), (1,3), (1,5), (1,7) ← Row 1 black squares
  • (2,2), (2,4), (2,6), (2,8) ← Row 2 black squares

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Modifying Display Output

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Board Borders and Labels

The board rendering includes borders and column numbers in the actualizar-tablero rule. Top border (line 310): 
(printout t crlf crlf" ------- ------- ------- ------- ------- ------- ------- -------"crlf)
Bottom labels (line 358): 
(printout t"    1       2       3       4       5       6       7       8 " crlf crlf)

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Customizing Messages

1

Game over message

Edit the finalizar-juego rule (lines 2036-2052):
(printout t crlf"GAME OVER" crlf)
(printout t "The cats win!" crlf)
2

Move prompts

Edit the pedir-movimiento-raton rule (around line 403):
(printout t crlf "Your turn! Enter row and column:" crlf)
(printout t "Row    [1-8] :")
3

Error messages

Modify validation messages (lines 416, 434, 482):
(printout t crlf "Invalid position! Try again."crlf)
(printout t crlf "That square is occupied!"crlf)

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Adding Color (Terminal-Dependent)

If your CLIPS terminal supports ANSI color codes: 
; Red text for cats
(pieza
  (valor 5)
  (parte1 "\033[31m /\\_/\\ \033[0m")
  (parte2 "\033[31m( o.o )\033[0m")
  (parte3 "\033[31m > ^ < \033[0m")
)

; Blue text for mouse
(pieza
  (valor 4)
  (parte1 "\033[34m(_)_(_)\033[0m")
  (parte2 "\033[34m (o o) \033[0m")
  (parte3 "\033[34m==\\o/==\033[0m")
)
ANSI codes may not work in all CLIPS environments. The \033[31m starts red text, \033[34m starts blue, and \033[0m resets color.

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Changing Board Size

Changing the board size requires extensive modifications to multiple rules and is not recommended without deep understanding of the code.

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What Would Need to Change

If you want to attempt a different board size:
1

Board initialization (lines 194-206)

Change the loop-for-count ranges:
; Original 8x8
(loop-for-count (?i 1 8)do
  (loop-for-count (?j 1 8)do

; Modified 6x6
(loop-for-count (?i 1 6)do
  (loop-for-count (?j 1 6)do
2

Rendering logic (lines 289-363)

Update all conditionals checking <= ?i 8, = ?j 8, etc.:
; Change all instances of 8 to your new size
(if (and (and (<= ?i 6) (< ?j 6)) ...)
3

Input validation (line 414)

Update range checks:
; Original
(if (or (> ?fila 8) (> ?columna 8) ...

; Modified for 6x6
(if (or (> ?fila 6) (> ?columna 6) ...
4

AI strategy rules

Many AI rules have hardcoded position checks. Search for comparisons involving specific row/column numbers and adjust accordingly.
5

Border rendering

Update the number of dashes and column labels in the rendering rule.
Changing board size will likely break AI strategies. Rules like mover-gato-mas-alejado-raton use hardcoded logic assuming an 8x8 board. Extensive testing and AI rule rewrites will be required.

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Adding New Piece Types

You can add additional piece types for game variations.

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Example: Adding a Dog Piece

1

Define the pieza

Add a new pieza fact with a unique valor:
(pieza
  (valor 6)  ; New piece type
  (parte1 " /|  |\\ ")
  (parte2 " ( ww) ")
  (parte3 "  WOOF ")
)
2

Place it on the board

In posiciones-piezas-iniciales, add:
?perro <- (casilla (fila 4)(columna 4)(valor ?))
=>
(modify ?perro (valor 6))
3

Create movement rules

Write new defrule blocks to define how the dog moves. Use existing rules as templates.
Adding new pieces requires creating corresponding movement rules and updating game-end conditions. This is an advanced modification suitable for learning CLIPS rule design.

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Testing Your Changes

After any customization:
1

Load the file

CLIPS> (clear)
CLIPS> (load "raton_y_gatos.clp")
2

Test basic functionality

CLIPS> (jugar)
Verify:
  • Board renders correctly
  • Pieces appear as expected
  • Input prompts work
3

Play a full game

Test several complete games to ensure:
  • Mouse movement works
  • Cat AI functions
  • Game-end detection works
4

Check edge cases

  • Try invalid moves
  • Move mouse to corners
  • Test win conditions

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Common Issues

Board alignment is broken:
  • Check that all parte strings are exactly 7 characters
  • Ensure special characters (like backslashes) are properly escaped
Pieces don’t appear:
  • Verify the valor field matches between casilla and pieza
  • Check that initial positions are on black squares
AI doesn’t move:
  • If you changed board size, AI rules may fail to match
  • Check CLIPS output for error messages
Game crashes:
  • Ensure all loops use correct bounds
  • Verify facts are being asserted and retracted properly

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