slope   - successes used to improve position (ie, to improve later
          successes); eventually large-enough successes are cashed.
          some small risks may be taken.
random  - successes cash immediately - risks are taken I guess to try
          and improve the cashing
perfect - successes used to make a defensive position. when a good
          shot can be taken, it's taken. risks not generally taken

1) at low levels, defense beats offense
2) at higher levels, offense beats defense
3) taking a shot opens you up on the next round
4) it's possible to improve your position later by work now, and this
   can accumulate over several rounds (you can improve both your
   offensive and your defensive position - possibly this is mutually exclusive)
5) you can also sacrifice your later defensive position for an
   offensive position now, but it seems like this should be less
   cost-effective than the other way around (since you pay a premium
   for getting it sooner) 

1) Each round there is a winner and a loser (or a tie). The winner
   wins by some number of degrees, and in addition each has an
   absolute score. 
2) There is an overall risk level monitoring how much danger people
   are in.
3) There is a health meter showing how much damage people can take. It
   is possible that losing points on your health meter causes a
   decline in your fighting skill. (Your actual risk must be
   calculated by taking the overall risk level and your health and
   position into account, since a very hurt person at low risk may
   still be in trouble)

Perfect is arguably a lower-risk version of slope, if you assume that
improving your defensive position now is the same as improving your
offensive position later; random is arguably a higher-risk version of
slope with a low version of 'large-enough'. 

Probably need rules for converting a position into defense or offense
bonus. Also need rules for worsening position later in exchange for
position now.