Provide a sample universal code snippet assuming a basic goal-seeking behavior and the ability to detect the finish line.

Sample Universal Code (Conceptual):

The following is a conceptual representation of a universal code. Actual implementation would depend on how the 'finish' is defined and how complex the branching logic needs to be.

// Assuming 'is_at_finish()' is a function that returns true if the character is at the finish line
while not is_at_finish():
    // Prioritize moving towards a general direction, e.g., right, then up.
    if free_from_right():
        move_right()
    elif free_from_up():
        move_up()
    elif free_from_down():
        move_down()
    elif free_from_left():
        move_left()
    // Add more complex branching for walls or specific field layouts if needed.
    // For example, if there's a wall, try to go around it.
    // else if wall_from_right() and free_from_up():
    //     move_up()
    // else if wall_from_right() and free_from_down():
    //     move_down()

// When the loop finishes, the character is at the finish.

Explanation:

• The `while not is_at_finish():` loop continues as long as the character has not reached the finish.
• Inside the loop, it attempts to move in a sequence of preferred directions if the path is clear (`free_from_`).
• This is a simplified reactive approach. A truly universal solution for varied mazes might require a more advanced algorithm like A* or BFS, which are typically implemented with more elaborate data structures.

Note: The exact implementation depends heavily on the specifics of the "three fields" and how the finish line is uniquely identified or reached in each case.