I'm not sure if this has been suggested or tried before, but I was thinking about a Challenge that goes against the grain. Often, we're trying to get more, more, more. This one is asking for more with less.
Title: "Go for Broke: Money Can't Buy Happiness"
Goal: In 12 sim-weeks, accumulate as much happiness as possible while keeping your family's net worth as low as possible.
Rules: Pretty much anything goes, except cheats.
((I haven't really thought this part out, so there's lots of room for improvement. Obviously, as someone who has access to ONLY
the Vanilla game, I'd want to limit the access to all Expansion Pack stuff, hehe))
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Edit: I've come up with what I think may be a simpler, and more effective, scoring system -- see post #895 below.
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Scoring: 1) Add up the Total Happiness points for every member of the household ("Household" is all Sims living under the same roof at the moment the Challenge ends). 100,000 is the default for any member who does not have at least 100,000 points..
2) Subtract Household Net Worth ("Household Net Worth" = value of furnished home plus Cash on Hand).
3) Divide by number of Sims in household. The higher your score, the better.
Example: The Delightful family has 8 members. Three of the members did not accumulate 100,000 points. The Household's Net Worth is 158,342.
Happiness Points = 345,678 + 234,567 + 123,456 + 123,321 + 109,876 + 100,000 + 100,000 + 100,000 = 1,236,898
1,236,898 - 158,342 (Net Worth) = 1,078,556
1,078,556 divided by 8 household members = 134820 final score (rounded up)
Edited to correct math errors