Wrestling

[Matarael]

Pin/Incapacitate on a natural 18, 19 or 20

What must the character be doing when they roll that?

As in, can he be wielding a knife and get an 18, 19 or 20 and pin/incapacitate?

Or must he be barehanded and trying to punch?

Or, should this be interpreted as he must call that he is trying to pin/incapacitate and hope to roll a natural 18, 19 or 20?

Any official rules on this?

Thanks.

[Killer Cyborg]

Pin/Incapacitate on a natural 18, 19 or 20

What must the character be doing when they roll that?

As in, can he be wielding a knife and get an 18, 19 or 20 and pin/incapacitate?

Or must he be barehanded and trying to punch?

Or, should this be interpreted as he must call that he is trying to pin/incapacitate and hope to roll a natural 18, 19 or 20?

He has to call it.
Otherwise, it would state that it doesn't have to be called (as with the KO in Boxing).

Any official rules on this?

Thanks.

Nope!
You might look in N&S for rules on locks and holds, though iirc those are pretty sparse too.