In order to make rules easier to understand at glance. It is recommended to use keywords. So instead of writting:
"This creature cannot be blocked"
You write
"Stealth (This creature cannot be blocked)"
Now the word stealth is a thematical keyword, I could have use a non thematical keyword like:
"Unblockable (This creature cannot be blocked)"
Now I was wondering in what direction I should go.
The thematic keywords have the advantage of justifying the ability making creature much easier to design. But is restrictive because it does not allow to use the same ability for other thematic reasons like:
"Flying (This creature cannot be blocked)"
"Borrowing (This creature cannot be blocked)"
In that case, that would make too much thematic keywords for the same ability.
If I use a mechanical keyword, then I can support any kind of thematical reason and it might be easier to remember that "unblockable" makes your creature unblockable than "stealth", but it weakens the theme of the game and make it harder to design creatures (less intuitive).
Which direction do you prefer?
I was thinking that it could be a problem because you generally try to remember keywords and that simply duplicate the number of associations you need to remember.
Just a weird spontaneous idea. How about using:
Unblockable (Stealth)
Unblockable (Flying)
Unblockable (Burrowing)
This means the the text in parenthesis is simply flavor text. But I could used indexed vocabulary to find the abilities. For example: "Hmm, what would flying creature have like ability" search "flying" and stumble on a series of abilities including unblockable.
This also means that the rules keywords needs to be short and self explanatory. Of course flavor text is optional.