The following applies to Avernum 3, but should also work for BoA.
"Reactivating the Character Editor for Macintosh and Windows
You can turn off the character editor permanently. Should you have done this and want your character editor back, this is how to restore it (written backwards for extra secrecy): fI gnisu a hsotnicaM, worht yawa eht "munrevA 3 sferP" elif ni eht secnereferP redlof. fI gnisu swodniW, eteled eht "tad.3munrevA" elif ni eht 3 munrevA ataD redlof. Please note if you have registered the game, this might unregister it. If your game becomes unregistered, contact us for a new key by calling 206.789.4438 or emailing spidweb@spiderwebsoftware.com. There is no charge for this but please include the name you registered under, which game you need a new key for and your current registration code (located in the lower right hand corner of the title screen)."