In The Merchant of Venice, aside from Antonio's "pound of flesh," the "lottery" to which Portia must succumb is a principal issue. Portia is an independent woman and most upset that "the will of a living daughter curb'd by the will of a dead father,"(I.ii.20) forces her to choose a suitor according to certain conditions. The suitor who correctly chooses the casket bearing her picture, will be her husband.
In Act II, scene i we are introduced to The Prince of Morocco, whose complexion is "of the burnish'd sun." (II.i.2) He is concerned that Portia will "mislike" (1) him, even though "the best-regarded virgins of our clime have loved "(10-11) his dark skin tone.
Portia points out to him that she is not a person who is "solely led by nice direction" meaning that she is not guided by just good looks. Anyway, her father's will, containing "the lottery of my destiny" prevents ("bars") her from making her own choice. Portia goes on to point out that, "if my father had not scanted me," restricting her choice and had not "hedg'd" or controlled her by his astuteness ("wit"), forcing her to marry the one who "wins me by that means," then The Prince of Morocco would have as much or as "fair" a chance as the next man in winning her "affection."
The audience is already aware of how Portia has discounted other suitors, such as "the Neapolitan prince" and the "Country Palatine" and her negative attitude, in having to keep to her father's wishes, as she remains loyal to him, is probably evident to the Prince of Morocco when he attempts to defend himself against her potential prejudice.