In 3.6e, spellcasters who have a limited number of spells per day are granted additional spell slots based on their casting stat modifier according to the table below. In order to receive the bonus spell slots, they must already be able to cast spells of that level.

Skill Bonus	Level 0	Level 1	Level 2	Level 3	Level 4	Level 5	Level 6	Level 7	Level 8	Level 9
1	1	1	1	0	0	0	0	0	0	0
2	2	2	1	1	1	1	0	0	0	0
3	3	3	2	2	1	1	1	0	0	0
4	4	4	2	2	1	1	1	1	1	0
5	5	5	3	2	1	1	1	1	1	1
6	6	6	3	2	2	1	1	1	1	1
7	7	7	4	2	2	1	1	1	1	1
8	8	8	4	3	2	2	1	1	1	1
9	9	9	5	3	2	2	2	1	1	1
10	10	10	5	3	3	2	2	1	1	1
11	11	11	6	4	3	2	2	1	1	1