The fourth mode of marriage, the vital, stands in sharp contrast to the previous three types, although these couples say and do many of the same things. (religion-online.org)
It is only in the fourth mode that genuinely abstract concepts are handled. (newscientist.com)
The fourth mode is a little more unique, dubbed Head Hunter, which has you killing enemies and then returning dropped orbs to a central location to score points for your team. (gaming-age.com)