Make it rare and a FeatI must respectively disagree somewhat with your perspective on this. Granted, we're talking about a fantasy RPG where anything is possible, so it's not a major point of contention.
Re "The proposal":
Concentration is all about the shifting balance between focus and distraction. As we hear about all too often in the news, drivers on their cell phones contribute to accidents, as do pedestrians on their own media devices.
Despite all beliefs and wishes to the contrary, our brains really cannot concentrate very well on more than one thing at a time. Multi-tasking effectively is all about how quickly we can shift our focus from one task to another, including recalling just where one was with the information pertinent to the new focus, and almost has more in common with urban legends than pragmatic reality.
Studies of multi-tasking over the last 20 years or so show that when multi-tasking, productivity diminishes to around 80% of the quality of what can be accomplished by concentrating on just one task. As we age, our ability to switch quickly between multiple tasks diminishes, as it takes a little longer to recoup that "where was I with this?" place.
So, I disagree with the idea of being able to concentrate on any number of spells as a normal function.
However, I share your frustration at how much this limits potential for a spell-casting PC. Hence, my counter-proposal:
Being able to maintain concentration on more than one spell at a time should be a rare and remarkable ability. How about requiring a Feat for it?
Enhanced Concentration. Pre-requisites: Spell-caster 8th level or higher; War Caster Feat.
Through diligent study and hard-won experience, you have developed the skill to maintain more than a single spell at a time.
- Increase your spell-casting ability score by 1, to a maximum of 20.
- You are able to maintain concentration on one additional spell for each time you take this Feat.
- The first time you take this Feat, you lose the Advantage on your Constitution saving throws granted by the War Caster Feat whenever you are maintaining more than one spell. If you take this Feat a second time, you regain Advantage on Concentration saving throws regardless of the number of spells you are maintaining.
- The DC for your Constitution saving throws to maintain concentration on the spells increases by 1 for each spell you are maintaining, including the initial maintained spell you cast. Normally, the DC is 10; for two spells it is DC 12, for three spells it is DC 13, etc.
- Failing the Constitution saving throw ends one of your maintained spells (player's choice).
Thank you, Sadrik, for raising this issue. May all your game sessions be entertaining.
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