This system involves you in using different basic low level magic to generate runes. The more you use certain skills, the more rune power it will produce. Some skills will generate more rune power than others. More special and powerful magic will require you to use rune power. To keep things balanced, skill cooldown is involved in this. Also, rune power is divided up into different elements, so you can’t just have a really big variety of spells. This would require you to specialize a bit.
Example: One skill may be able to produce 15% rune power but the cooldown for that skill will be 2 seconds as compared to another skill that may produce 5% rune power but has a 1 second cooldown.
Below is a diagram of what the rune bar would look like.