Counterspell Errata

Issues

• The spell allows the caster to use his reaction and a 3rd level slot to potentially interrupt a spell of any spell level. This is too good of a trade - the caster loses a reaction and a 3rd level slot for the chance to "eat" an opponent caster's higher level slot AND that caster's action.
• There are no rules regarding identifying which spell is being cast by an opposing caster. This may seem trivial, but it is not. For example, both Faerie Fire and Teleport are verbal-only spells; things that nominally take but a word to cast. The 5e magic system provides no way for an opposing caster to know which spell is being cast, let alone the ability to do so in the moment between one of these spell's verbal beginning and its end. Counterspell itself is a somatic-only spell. Presumably this can itself be Counterspelled, but doing so means that the caster of this second Counterspell can interpret the gesture before the magic takes affect.

Fix
The spell operates as written except for the following changes:

• Counterspell has no ability to disrupt a spell if that spell is cast using a higher level slot than the slot used to cast the Counterspell.
• The caster of Counterspell must be able to target the caster casting the spell he wishes to disrupt. All rules for targeting a creature apply.
• This spell can be used to disrupt all spells cast by normal means; that is, by any creature that uses the spellcasting ability and has spell slots. This spell cannot disrupt spells that originate from magic items, that are cast using Innate Spellcasting or that occur because of Psionics.