Bounding Boxes and Prone

The original Firearms had a unique prone system: going prone was slow, but with the skill Battle Field Agility, it was faster. Later versions changed this up some, making the standard prone faster and BFA only slightly more so. Another problem with prone in older versions is that the bounding boxes - the boxes that dictate where your character "collides" with the world - were very inaccurate. Players who were prone could not enter crawl spaces that they could while crouched, nor pass though narrow passages that they could while crouched or standing.

While FAS is going back to the older version of Firearms in terms of game play and "feel", the prone system is vastly updated, according to Hitman. The speed of going prone is fast to reflect the game play. It makes little sense for people to be sprinting around, jumping over sandbags and hurling grenades to be unable to quickly go prone. Additionally, the bounding boxes of prone are more accurate, reflecting character's real height: while prone, you are able to go under objects that you couldn't go under while crouched (but this still needs some more testing before release).

The fate of BFA is somewhat in question with the quick prone and lack of stamina drain while moving which were the two of the three main reasons for BFA in previous RCs; the last being able to fall at great distances without breaking your leg. As FAS does not have broken legs implemented yet, BFA as a unique skill seems unlikely.