Adding a feature or additional function to an item is simpler than creating something new. You don't need to invent a special formula or plan. Make a crafting roll to modify an item (the baseline quality of an item that you modify is equal to your crew's Tier, as usual).

• A simple, useful modification requires Tier +1 quality. A rifle that breaks down into two sections to be more easily concealed.
• A significant modification requires Tier +2 quality. Strengthening the barrel and powder load of a gun to fire further.
• An arcane, spark-craft, or alchemical modification requires Tier +3 quality. A dagger that can harm a demon. An electrified hull on a boat to repel boarders or ghosts. An outfit coated with chemicals to mask you from deathlands predators.

Modified items, like special creations, may have drawbacks.