Play in which game mode?

t - Tutorial
    Gain hints about controls and gameplay, while playing an otherwise normal
    game. Tutorial games are eligible for scoring, if you do well enough.

x - Explore mode
    A more forgiving version of the game, for experimentation; save files can
    be loaded without deleting them, you resurrect infinite times upon death,
    and you start with a free wand of wishing. Not eligible for scoring.

n - Normal mode
    The normal game. Death is permanent and deletes your save file.

s - Solo mode
    A version of the normal game slightly modified to prevent interaction
    between players; all levels generated will be fresh, rather than copied
    from the bones of previous games. You also do not see your character's
    stats until you start playing.

d - Debug mode
    Gain free rein over everything that exists in the game world, for debugging
    the game. The game may not be stable in this mode, due to the ability to
    change game internals. Obviously not eligible for scoring.