It is possible to steal the same spell, effectively having a multiple copy of that spell on your skillbar. Show caution when using Echo, Arcane Echo, Arcane Thievery, or Signet of Humility in conjunction with this skill as it will not increase the chances of stealing different spells, it will select randomly.
The stolen spell is linked to your attribute and not the opponent's.
The disabling effect of Auspicious Incantation does not affect Arcane Larceny. So if you use Arcane Larceny with it you can use the copied spell right away.
If you steal a maintainable enchantment, its effects will still work until you remove it, even when Arcane Larceny changes back into itself.
During battle, if the stolen spell is from a campaign which you do not own, it will remain locked/unusable.