public void incCredits(float inc) {
    if (Float.isNaN(inc)) I.complain("INC IS NOT-A-NUMBER!") ;
    if (Float.isNaN(credits)) credits = 0 ;
    if (inc == 0) return ;
    final int oldC = (int) credits() ;
    super.incCredits(inc) ;
    final int newC = (int) credits() ;
    if (! venue.inWorld() || oldC == newC) return ;
    String phrase = inc >= 0 ? "+" : "-" ;
    phrase+=" "+(int) Math.abs(inc)+" credits" ;
    venue.chat.addPhrase(phrase) ;
  }