No it isn't. Here we go:Originally Posted by Springer
Armored Core 1 (PS1)
Armored Core 1: Project Phantasma (PS1)
Armored Core 1: Master of Arena (PS1)
Armored Core 2 (PS2)
Armored Core 2: Another Age (PS2)
Armored Core 3 (PS2)
Armored Core 3: Silent Line (PS2)
Armored Core: Nexus (PS2)
Armored Core: Nine Breaker (PS2)
In case you haven't noticed, there is no numerical AC4 yet. Nine breaker is not AC9. It is titled that because it's a raw tournament game. Once you pass the tenth rank, you are considered a "Nine Breaker". Also because there is an AC of legendary status called "Nine-ball" Not because it is AC9.