It's a staple of the Sims series that once you reach the top of a career chain, you get some sort of fancy doo-dad. In The Sims 3, once Harlan Whyte was promoted to mad scientist, he earned a new interaction. For certain objects, one of his choices for interaction is "perform experiment on".

The result is what you see in that screenshot. You can't see it, but off to the left is his XS 4258p Laptop from Landgraab Industries. Once he was done, the laptop emanated a sort of freaky Matrix-ey effect. Now, whenever someone uses the laptop, that sim acquires a moodlet called "Oddly Powerful". It gives the sim's mood a 15-point boost and lasts for two hours.

Moodlets, you ask? They're the building blocks of gameplay in The Sims 3. Mood has always been a central tenet of the Sims series. It's a bottom line measurement of your sim's well being. In the past, the primary determinants of mood have been a sim's needs bars: hunger, energy, social, that sort of thing.

But that's no longer the case in The Sims 3. Your needs bars will affect your mood, but only through moodlets, which are, quite simply, buffs and debuffs. Each one has a duration and a positive or negative effect on your sim's mood. If you need desperately to pee because your bladder bar is empty, you get a negative moodlet until you see a man about a horse. If you're well rested, you get a positive moodlet for much of the day. If you've just brushed your teeth, you get a brief positive moodlet from the minty fresh. If you're humiliated due to a social faux pas during a conversation, you get a negative moodlet. And if you use Harlan Whyte's XS 4258p Laptop from Landgraab Industries, you get a positive moodlet for two hours because you feel oddly powerful.

Tomorrow: Is that a moodlet in your pocket, or are you just happy to see me?
(Click here for the previous Sims 3 game diary.)