User blog comment:Master Sima Yi/Assassinews 02-08-'12 — Official AnvilNext Trailer/@comment-101.173.42.147-20120803114042/@comment-5266147-20120803124613

but the combat includes fighting on rough terain, only some of the new stuff would have been possible to include with extending the old engine, thats why a new one was built. personally i feel building a new engine should always be the preference if your doing anything more than minor improvements, and is a must when your completely overhauling and improving on global features as ac3 is.