Con

(not to be confused with [CON] which is short for constitution)

Con is a feature of outcome consideration, or estimate on the level of mob encounter to the player's character or party level (party level is simply the highest level member of the party).

Basic Information
The con system in Stash tells you the relative level of the monster you are about to fight to your own level. When you mouse over an encounter, the color of the text as well as the color of the base underneath the monster, will let you know the average level of the encounter in comparison to your own.

Etymology
Con is short for consider which was a text command for evaluating the outcome of combat in MUDs. In such text-based MUDs the results of a consider were expressed verbally as "easy peasy", "you would need guts", or "you ARE mad", but in modern graphical games results are color-based as green indicating a weaker target, white a close match, orange and red indicating a strong target, and purple indicating total outclassing. While the indications can be questionable due to a player's individual capabilities, con still gives you an idea on which opponent is stronger.