Nifft, I'm not talking about spell slots that have "--" listed. I'm talking about spell slots that have "1" listed. For those slots, where you get a bonus spell, you get that bonus spell slot by virtue of having a high intelligence. You don't get it through experience. Look at the Spells Per Day table for the wizard class. At first level, you can cast 3 0th level spells and 1 1st level spell. For 2nd level spells, 3rd level spells, etc, it has "--" listed, meaning you can't cast those spells at all. But under the bonus spells table (next to the general ability modifier table), it shows that ALL wizards with a 17 Int have a bonus 3rd level spell per day. Again, obviously you can't use that slot to cast a 3rd level spell until you have actually LEARNED a 3rd level spell (which comes with experience). But the slot is there from the very beginning, assuming you have a 17 Int.