Smoke runes are combination runes. They count as two separate runes: one Fire runeand one Air rune. Thus, any spell requiring one Fire rune, one Air rune or both will cost only one Smoke rune. The value of 1 Smoke rune in Mobilising Armies is 7 Investment Credits.
Tiaras can't be used in place of talismans while crafting combination runes. Players receive 8.5 experience for combining fire runes at an Air altar and 9.5 for combining air runes at a Fire altar.
Combinations have a 50% success rate (or 100%, if the player is wearing a binding necklace), and the talisman is consumed in the process (unless the player uses the Lunar spellMagic Imbue).