I have a special interest in faireness. There's a technical definition in mechanism design: a mechanism (say for allocating goods) is Fair if all participants derive equal utility from participating. Compare to Efficiency: total utility is maximized (each good went to the person who wanted it most). You get both fairness and efficiency by having the winners pay the losers just enough so that the losers are as happy with the money as the winners are with the booty minus the money. A related mechanism property is envy-freeness: no one would prefer to trade places with anyone else.