should crennelations provide normal or improved cover?

[The Sideromancer]

And I don't mean the wimpy ones seen in most fantasy either. I mean ones with the merlons full-body height and the crenels still at waist-height. In other words, using a map,

###E###
_%_%_%

(elevation difference)

P

Secondly, would including machicolations (holes at the bottom to allow for easier firing downwards) change this answer?

I've finally lost my patience with people hating on defensive play.

[The Sideromancer]

Or is it better to have fully enclosed wooden battlements to keep flyers out?

[Claxon]

Since the example of improved cover is an arrow slit, I would say that if you're making an attack from between the merlons you would not have improved cover.

Of course, if you don't care too much about action economy, you could 5ft step from behind the merlon, attack, drop prone as a free action (gaining total cover). Next turn you move 5ft behind the merlon again, and stand up. Next turn you 5ft step out, attack again, and drop prone as a free action. Repeat as needed.

Of course a fireball or a flying enemy defeats this tactic easily.