NetHack units

Synopsis

Many have tried to convert Nethack units of measurement to more or less correlate with real life. This attempt uses metabolism as the transition factor. The result was approximately 7.5 seconds/turn, which seems to be within proper degrees of magnitude. The translated Nethack time will be called Correlated Nethack Time, or CNT.

Calculation

According to the guidebook, divine intervention was certainly sufficient to influence sleep of the chosen hero ("Strange dreams... haunted you in your sleep"). Therefore, it can be extrapolated that whilst in the dungeon (or gehennom), magical or divine influence allowed the hero to not require regular sleep. This explains why no occurances of mandatory sleep occur through the game.

Assuming, then, that the hero hacks continuously, and that hacking is hard work, the hero's caloric consumption can then be calculated. Averaging the energy spent during combat and the energy spent leisurely exploring, the caloric consumption should be somewhere around 400 Cal/hour, which is equal to a brisk walk for a human of 80 kg.

Hero consumes $400 Cal/h$ continuously (no sleep).

Since food rations are frequently in the hero's inventory from the start, it can be safely assumed that food rations are not magical products, but designed for normal mortal humans to eat three times daily with a daily consumption of 2000 Cal / day.

$\frac{\frac{2000 Cal/day}{3 rations/day}}{400 Cal/h} = 1.67 h/ration$

In Nethack, one ration is 800 nutritional points, which lasts 800 turns in standard hacking conditions. Therefore,

$\frac{800 turns/ration}{1.67 h/ration} = 479 turns/h$

$\frac{3600 s}{479 turns} = 7.52 s/turn$

Extrapolations

With this core value of 7.52 seconds/turn in mind, one can calculate the scale of magnitude of other values in the nethack world.

An average ascension is 50000 turns, this means that:

$(50000 turns/ascension)(7.52 s/turn)\left (\frac{1 day}{86400 s}\right ) = 4.35 days/ascension$

4 days and 8 hours of Nethack time seems reasonable for an ascension.

A human walks at approximately 5 km/hour. This means that one Nethack tile is:

$(5km/h)(\frac{5 h\cdot m}{18 km\cdot s})(7.52 s/tile) = 10.4 m/tile$

This seems reasonable, as a dragon has to fit into one. Ceilings should be about this high as well, seeing that going up and down stairs take a similar amount of time.

A dungeon level's dimension limits are 71x19 (80x25 minus borders and status lines). This means a dungeon is approximately 700m by 200m (roughly, 1/2 mi by 1/8 mi).

Results

The Hero:

• ... consumes 400 Cal/hour continuously (no sleep).
• ...7.5 seconds is one Nethack turn.
• ...An average ascension is 4 days and 8 hours of Correlated Nethack Time (CNT).
  • ... rast's record fast ascension took 13.5 hours CNT.
• ... one Nethack tile length should be about 10.4m (34.1 ft).
• ... dungeon dimensions are approximately 700m x 200m (1/2 mi x 1/8 mi).