What is 'floating mana' in Riftbound and how does it work?

Ruling: 'Floating mana' refers to exhausting a rune to gain 1 energy before recycling that rune. The energy persists for your entire turn and can be used at any point during that turn.

Sequence:

• Exhaust the rune to gain 1 energy
• Recycle that same rune
• Use the energy at any point later in your turn

Nuances:

• The rune must be exhausted before recycling it (you don't exhaust it after it's already been recycled)
• Energy sticks around for your whole turn once generated