Like a
d100 only more so.
A
d1000 is a roll used ocasionaly in some
RPGs and
wargames. It is almost always generated by rolling 3 differntly
coloured d10, having stated each colour is either the hundreds, tens, or units digit. Alternatively, if you are a so cool as to have one, roll a
physical d100 for tens and units, and a d10 as the hundreds digit. The d1000 is usualy only used for very large
randomization tables, or for large tables where having
significantly different ranges for different results is considered to be important.
For example
Men & Supermen contains the following table for generating
blood type;
001-384 O Positive
385-461 O Negative
462-784 A Positive
785-849 A Negative
850-943 B Positive
944-960 B Negative
961-992 AB Positive
993-999 AB Negative
000
Mutated Blood
Let's say i have
red,
green and
blue d10. I say that red is hundreds, blue is tens, and green is units. I roll the dice and get 9 on the red, 5 on the blue and 0 on the units. This gives 950, which is B negative;
my blood group
IRL, if you care. A d100 roll would not
suffice for this as AB- and mutated are so rare. Although it could be done with a d100 and
subtables, it's more effort.
AFAIK a physical
manifestation of the d1000 does not exist. It's possible one's been made, but it would be
football sized, need a huge surface to roll it on, and probably not be fair.