TL;DR
Better not to. Reheat only the portion you're about to eat, because rice carries a bacteria risk that reheating can't fully undo.
Rice has a reputation problem that's actually earned. Raw rice can carry spores of Bacillus cereus, a bacteria that survives cooking and can multiply if the rice cools slowly or sits out — and the toxin it produces doesn't break down when the rice is reheated again.
That's different from most leftovers, where reheating to a high enough temperature kills the bacteria that could make you sick. With rice, the danger isn't only about bacteria at the moment you eat it — it's about what happened during every cooling and storage cycle before that.
Why rice is a special case
Bacillus cereus spores can survive cooking and germinate if cooked rice sits at room temperature. As the bacteria multiply, some strains produce a toxin called cereulide, which causes vomiting within a few hours of eating — and that toxin is heat-stable, meaning reheating the rice again, even to steaming hot, won't destroy it. This is sometimes nicknamed fried rice syndrome, since takeout rice left at room temperature for hours is a classic setup for it.
How to cool and store rice correctly
Cool cooked rice within about 1 hour of cooking rather than leaving it out to cool slowly on the stove or rice cooker. Refrigerate it at 40°F (4°C) or below, and eat it within 3-4 days. Spreading rice on a shallow tray or in a wide, shallow container for a few minutes before refrigerating speeds up cooling and limits the time bacteria have to grow, similar to the shallow-container trick used for soups and stews.
Why twice isn't really the magic number
Reheating rice once, thoroughly, to 165°F (74°C) with a little water splashed in to loosen it up is generally fine if it was cooled and stored correctly the first time. The real risk builds with every extra cycle of cooling and reheating, because each cycle is another window where the rice can sit in the 40-140°F (4-60°C) danger zone. Reheating the same portion a second time roughly doubles that exposure, so it's better to portion rice into single-serving containers before refrigerating and only reheat what you'll actually eat.
What to look for before eating leftover rice
Rice that smells sour, tastes off, feels tacky or slimy, or has been sitting at room temperature for more than 2 hours (1 hour above 90°F/32°C) should be thrown out, no matter how many times it's been reheated. When rice was cooled quickly, refrigerated promptly, and reheated once to steaming hot, it's one of the safer leftovers in the fridge. Restaurant fried rice is a common source of this specific illness precisely because large batches cool slowly in bulk containers, so home-cooked rice handled with quick, shallow cooling actually has an advantage.
Rice isn't cursed, but it doesn't forgive sloppy storage. Cool it fast, portion it out, and reheat each portion only once.