Aren't these usually +1 and -2? This could go on forever.
Not in versions were I make the rules!
As we have less characters left, the amount of points you can add/remove increases. In the DS9 version of this game we played with similar rules, and it went pretty quickly until we got to the last 6 (Garak, Kira, Damar, Weyoun, Odo and O'Brien). Then it became a slow epic showdown.