Can Staves, Metamagic Rods, and Other Slotless Items Be Combined Into a Single Item?

Question

Under the magic item creation rules, can a character create a single item which can function as either a stave or as a metamagic rod or as a Pearl of Power? Would this incur a cost increase/decrease over creating each of these items individually?

On one hand, this combination improves action economy since the character only has to draw the combined item once, rather than drawing each component item separately. On the other hand, it constricts the versatility of the combined item, since each of the component parts cannot be split up, sold, or given to other party members.

These items are all slotless, so there should be no cost penalty, but on the other hand they all have to be held to use, which one could say constitutes a slot in some fashion or form. On the other hand, their granted effects are all mutually exclusive and you can only use one in any given turn.

Answer 1

First of all, item crafting and pricing is more of an art than a science and requires GM oversight. A player will need their GM's assent to craft weird custom items and can't just interpret the rules themselves and then go ahead.

Given that admonition, there's various things that come to bear here.

Multiple Different Abilities: Abilities such as an attack roll bonus or saving throw bonus and a spell-like function are not similar, and their values are simply added together to determine the cost. For items that take up a space on a character's body, each additional power not only has no discount but instead has a 50% increase in price.

And from the magic item gp estimation chart,

No space limitation | Multiply entire cost by 2 | Ioun stone

Assuming you're adding up prices already with that x2 included in it (like the pearl of power), then yes, it should be simply additive to create a combo slotless item of all three of those devices.