Copy Cat

As you see someone or something cast a spell you quickly thrust your open palm forward feeling the magic energies being used to conjure the spell. The cantrip expands your eyes, ears and your mind to perceive and remember for a few seconds how to repeat a spell being cast, then temporarily locks the magical sequence into your mind.

With a successful arcana or insight check (caster's choice), you can ready any spell you just witnessed cast within 60 feet of you. The spell must have either Verbal or Somatic components (or both) to cast Copy Cat and can not be used on a spell that was cast from a magic item.

"Copy Check" make an Arcana or Insight check using the chart below to determine the DC: (Special: If you are a Tabaxi you get a +2 on this check.)

• Greatly Favorable DC: A spell you have already successfully copied 3 or more times from the same caster: DC 10 + Spell's level
• Favorable DC: A spell that you can clearly see with somatic and/or hear if verbal and understand the language it was cast in: DC 15 + Spell's level
• Unfavorable DC:  A spell that you can clearly see with somatic and/or hear if verbal and understand the language it was cast in but it was hard to hear or see how it was cast. DC: 20 + spell level.
• Unfavorable DC: A spell that you can clearly see with somatic and/or hear if verbal and do not understand the language it was cast in: DC: 20 + spell level.
• Greatly Unfavorable DC: A spell that the current situation makes it very hard to understand how the spell was cast: DC: 20 + spell level with disadvantage.

The DM decides if conditions were favorable or unfavorable for you to understand the spell you just witnessed. Example: Your DM may decide that if you witnessed a spell cast during a windy thunderstorm that it was hard for you to see and hear all the details to copy the spell. 

Casting Copy Cat followed by a Successful Copy Check only readies you to cast the spell. You then have until the end of your next turn to cast that spell. Once cast, the spell copied then uses up a spell slot 1 level higher than normal. For example: You use your reaction to cast Copy Cat after seeing someone cast Lightning Bolt (A level 3 spell that requires 1 action to cast) After making your successful performance check you have until the end of your next turn to cast the Lightning Bolt as a standard action, assuming you have a level 4 spell slot to use up. Then all conditions, components, requirements and variables to cast the spell take place just as if you cast the spell normally. 

You use your Charisma modifier as your primary casting stat for the Copied Spell. 

Special Rule: 5th edition rules do not describe what language magic is cast in, further more, it is already assumed that magical verbal components are some rare and unique words that don't make sense to most. But for this spell, and at the DM's discretion, it is assumed that the caster casts in their primary language. By default, most casters cast in common, elves cast in elven, dwarves cast in dwarven, dragons cast in draconic and so on. Exceptions might be a human sorcerer with a dragon patron might cast in draconic. An evil wizard who has learned spells from the Book of Vile Darkness may be casting in infernal. 

Design Notes: I made this spell to make the bard class more fun and versatile. I feel the cost and DCs fall in line with it not being over powered. As is, this spell allows a bard to cast a spell that is already able to be cast in a D&D party but at the cost of a higher level spell slot, and the bard must also have a reaction available to prepare it while the spell happens to be cast. Lastly, the DCs are designed to make it so that the bard player should be able to copy his team mates spells most of the time, but provide a good challenge to copy enemy spells.