Feature, not bug. Rd 1: The wizard gets jumped. They cast the Blur equivalent as a reaction to try to avoid an attack. They then cast a concentration spell (Hypnotic Pattern?) on their next turn. They get to their next turn and use a bonus action and 4th level slot to cast a 3 rd fly spell using another of my spells. When their next turn comes, they lose that Blur.
This makes the character hugely powerful. Yes it is a feature that would make it WAY out of proportion to other martials.
This is anathema to the 5E design - but it is not broken. I've had this at my game tables for years now and it is not problematic at all.
You're missing the opportunity cost. Casting defensive spells means you are not being offensive.
You are letting them cast them as a bonus action, so there is almost no oppotunity cost. Further some spells like Hex can be cast well before a battle.
Go back to AD&D. In that era, how did wizards operate without a concetration limitation? Generally, they cast a bunch of defensive spells before combat - but once it began they spent most spells on offense.
I cut my teeth on 1E and they operated by drawing an opportunity attack every time they cast a spell in melee, from every enemy in range, having D4 hit points and having very weak spells, had fewer total spells to cast and fewer options on what to cast.
Shield was AC4 and had to be cast on your turn, blur was a -2 to AC and mage armor did not exist. Casting any of these in melee would trigger an attack on you and if it hit they were disrupted and did not take effect. Also you had to choose exactly what spells you were going to cast ahead of time - prepare 1 blur and you can only cast it 1 time the whole day.
In most combats in 1e Wizards threw darts (because you got 3 attacks a round with them). In major combats they would generally use their limited offensive spells for the day, usually trying to do it far away from the action.
In 5E, how often do people use defensive spells like blur in combat?
That is the second most common spell my bladesingers cast (most common is shield) and it would be on any Gish I played that had access to it. It is also cast A LOT by Artificers and Eldritch Knigts or other Gish dips.
Overall I would say Blur is one of the top 10 spells cast period along with shield, Hex, magic missile and healing word. Among 2nd level spells the only spell I can think of that are cast more often is shatter and misty step, and misty step only because it comes on an awesome feat making it available to everyone.
Rarely, They'll cast blink before combat.
They don't need to. They have the ability to cast it as a bonus action based on the write up above.
They'll use Shield. but do they devote that precious concentration to a defensive spell, or do they use it n something that takes enemies out faster?
Yes all the time - Protection from Good and Evil, Blur, Spirit Guardians, Greater Invisibility
I think those are the most commonly cast concentration spells of 1st, 2nd, 3rd and 4th level. Can you name any concentration spells of equal level that are cast more often than these? All of them can target only the caster if you play with your changes.
I think you have to go all the way to 5th level and Animate Objects to find a concentration spell that does not target the caster and is cast more often.
This put defensive spells back on the menu, and defensive spells in 5E are not so powerful as to make them no brainers for your use of spell slots even without the concentration limitation.
Greater invisibility makes you immune to the vast majority of enemy spells that enemies could target you with. It is extremely powerful against any enemy caster that does not have blindsight. You are also taking away one of the main counters to it - throw an AOE and try to break concentration.
This is aside from a new tactic of spamming regular 2nd level invisibility as a bonus action while you use your action for something else (or just stay invisible while you maintain concentration-free spirit guardians).
When did you cast that offensive spell?
Does it matter? I can cast it while not concentrating on the concentration buff.
Also let's not mix up offense vs defense. Your ability would apply to "spells that target you". That would include things like Dragons Breath, Shadow Blade and Spirit Guardians.
As Shield, Blink, and all the other non-concentration spells do not end, as well as spells cast on you with concentration by another caster. That is an illusory problem.If used as a bonus action action, you can't cast something else so you're limited to your weapon attack or cantrips for offense on those turns.
You are a GISH weapon attacks are your thing.
Bladesingers using their weapons most of the time to attack are not generally the stronger Bladesingers.
They are when you are throwing out action spells as bonus actions.
Blink for 5 rounds or blur for 2 or 3.
Blur for 3 rounds then recast it as a bonus action for another 3 .... or just use extend spell and get 6 rounds right off the bat.
