De or het hex?

The correct Dutch article is:

het hex

Meaning (Dutch) bep. bordspel

How to use hex

the hexhet hex
this hexdit hex
that hexdat hex
our hexons hex
your hexjouw hex
every hexelk hex
which hex?welk hex?
a big hex / the big hexeen groot hex, het grote hex

Dutch words ending in hex

narthex

In compound words, the last part decides the article. See the rule

Dutch words starting with hex

hexaan | hexachord | hexaëder | hexagoon | hexagram | hexameter | hexode

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).