When asking a rules questions, we ask that you quote the rulebook, as someone of us don't have the Rulebook readily available, or it might be in some obscure part.
I tried to find the specific instance you are talking about, and I can't find it. You are absolutely allowed to have more than one of the same spell, so I am unsure what sentence you are referencing. I have provided some basic quotes from the
Rulebook (Pages 101-103) below. I hope they help.
Spheres of Magic
"When the Sphere of a particular spell is referred to in Underworld, the spell is being referred to in terms of what it accomplishes. Spheres include, but are not limited to: Healing, Protections, Elemental (Fire, Water, Air, Earth), Nature, and Psionics. Note: spells may also be represented in several Spheres, but are different in terms of their origin.
Spheres are purchased in list form, with each spell becoming accessible to the caster when they have purchased the appropriate spell-slot. This means that until the appropriate spell-slot is purchased, the character cannot cast the spell, even though they do have in-game knowledge of the spell and what it does. They simply have not been able to master it yet. In short, buying the Sphere gives the character practical knowledge regarding the casting of the spell, but buying the slot represents the ability to channel the Magical energies necessary to cast the spell. The first Sphere of Magic is relatively easy to buy. Subsequent Spheres become more difficult to learn."
Spells
"A "Spell Pyramid" is the term used to describe the whole system of spell slots that a character purchases. There are rules governing in what order, and how many, spell slots a character can purchase at a given time. It's referred to as a "Pyramid" because looking at the diagram of spell slots a character has purchased, the base (low level
spells) must always be larger or equal to the rest of the Spell Pyramid. Some rules follow:
- In order to open up a spell slot for purchase, a character must have already purchased two spell slots from the level below it. A second spell slot of the same level would require the character to have purchased three spell slots of the level below it. This pattern continues until they are 5 spell slots wide. The obvious exception to this rule is level 1 spell slots.
- You may not exceed 5 spells slots wide, on any circle (level) until your entire pyramid is full. This means 5 spell slots wide up to your 9 th circle.
- Once you have a column pyramid of 5 wide and 9th circle high, you may expand outwards to a maximum of 10 wide. You may ignore the need to build in a pyramid but must still purchase the lower circle spell slot in order to purchase a spell slot from the circle above it. You may never have a higher number of circle spell slots then you do lower circle spell slots. Example: you may have eight 1 level spells or seven 1st level spells and seven 2nd level spells, but you may not have seven 1 level spells and eight 2nd level spells.
- The highest level spell slot available is 9th level. For more powerful magic beyond that, see the section on Ritual Magic."
I hope those excerpts are helpful.
