It's decent damage doing nothing in combat but spamming damage. Doing anything else in combat drops the damage and doing nothing but damage means it's playing one-trick-pony. Picking up eldritch blast is a at least adding a damage option while hex really does lock out a lot of good spells if concentration is always being used for that spell.
Action economy prevents doing that damage and doing other things. You can shore up the squishiness a fair bit too but that comes at the cost of something else. We could change the name to "walking opportunity cost" and it would accurately reflect bards.
Character levels? The fireball potential goes up 1d6 per 2 levels and applies to a single round of combat. Sneak attack scales up at the same rate but applies to each round of combat. That's going to favor rogues.
Bardic inspiration dice are definitely useful. So are other class features in the class and in other classes. Song of rest at 2nd level in a 5 PC group that takes 2 short rests can spend 1 HD each on each short rest to multiply that out to 10d6 bonus healing. The bard will be doing that regardless, and even though the scaling isn't impressive it's really helpful at low levels.
Let's work with it. Your support sucks with what's given so far. It's mob damage and weak healing, and the damage really isn't anything yet at 6th level using secrets for fireball and eldritch blast.
Forget secrets for the cantrip. Go variant human, use a feat if you weren't already. Unless there is something you really want in the warlock cantrips or a single shot 1st level spell you should take spell sniper for double range and ignoring cover to get eldritch blast. It will still use your CHA and won't matter on that it's not a bard spell for you.
1 -- light, prestidigitation, sleep, healing word, heroism, unseen servant
2 -- thunderwave
3 -- lesser restoration
4 -- minor illusion, magic mouth
5 -- leomund's tiny hut; swap sleep out for dispel magic
6 -- fireball, spiritual hammer or healing spirit
That list might seem a bit odd. Heroism is your go to spell for damage mitigation if you need it. Using it will cost you damage in the first round. Heroism will become a decision point in every battle for the use of that slot to balance out damage mitigation versus damage so you might want to hold off on spiritual weapon; an efficient healing spell takes pressure off that decision point. Healing word is strictly for emergency healing.
It's tempting to take hex at 6th level. It's not worth it. d6's on 2 attacks won't net as much damage as spiritual hammer will using it on important fights. Spiritual hammer also doesn't take concentration so heroism can be used if needed. The alternative to spiritual hammer is healing spirit. It's damage or healing but not both.
Thunderwave scales up to the same damage as shatter in the same slot anyway. Range is shatter's advantage and knocking targets away is thunder wave's. That nets you an AoE one level earlier and if you'd rather have shatter just trade it up at 3rd level when you add lesser restoration.
Slots are going heavy on damage. That's why leveraging the ritual caster feature is important. They will still be interrupting concentration so we'll be clearing 1st level spells out. Leomund's and unseen servant are obvious choices. Magic mouth doubles as a messaging system, alarm, or diversion.
Spells after 6th level need to work around using fireball for damage. That means either they are rituals (unlikely) or the bard expects to situationally use them. Otherwise, the fireball damage does not occur and kills the concept early because of the slot bottleneck.
7 - improved invisibility
8 - dimension door
9 - raise dead
10 - thunderclap, hex, healing spirit or spiritual weapon; swap heroism for greater restoration.
You mentioned wave of destruction a few times. It's not worth giving up something else. Improved invisibility is one of the few concentration spells on this list, but if someone really needs to hide fast it's there. Plus, you cannot be counterspelled facing other casters if they cannot see you.
11 - True seeing
13 - Teleport
14 - Disintegrate, Plane Shift
More spells to cover a wizardly trope. Disintegrate is the big one here. It bypasses the friendly fire issue the build has with fireball. We're going mostly with utility here instead of status effects to keep away from concentration and needless action conflicts.
15 - Dominate Monster
17 - True Polymorph
18 - Wish, Sunburst
It's nowhere near the support a cleric has, and it's also nowhere near the range of a wizard. It is a decent blended list with a lot of utility, low to moderate healing, and decent damage options. The spells tend to be trailing behind in gaining them but that's the way secrets is designed. There's you're red mage build.
Yes it is decent enough and it is patterned after a wizard style. It's still behind and tweaking it requires giving something up in any direction it's tweaked. Divinations are lacking so drop healing, or damage, or some of the other utility spells for them; or work the skills system you were poopooing earlier.
It's also lacking in defensive spells but the bard list suffers a lack there and grabbing from other classes is a giving something up again. That's hard to accomplish because there aren't enough magical secrets to pull much off. ASI's at 4th and 8th level, war caster or resilient CON at 12th level so a person might sneak a minor defensive boost at 16th level in the feats.
The closest thing to fighter this fits in is light armor and a couple weapon proficiencies.
This is just a quick brainstorm, so if you have suggestions or want to discuss why it's pretty far behind clerics or wizards in detail we can do that.
The lore bard still isn't good at the damage, just decent enough, lol.
Mr Rogue is good with looking for a magic weapon or letting a party member who does better support help out. The example I gave above stated destructive wave isn't worth it. It's not. Shatter is still there as a back up AoE that's rarely resisted immune, and disintegrate is added for force damage that's higher than destructive wave. The only thing you are really getting out of destructive wave is the status effect, and to get it you need to drop something else, and it's got to be other magical secrets that you are giving up.
There's no Shrodinger's Bard going on here. You are waiting until 14th level for wave of destruction which is pointless given disintegrate becomes available; or you are giving up hex, or healing spirit, or spiritual hammer; or you are giving up fireball and delaying that AoE damage in the meantime.
You were just giving up damage or the only worthwhile healing you had for destructive wave. The damage is behind most even fireballing your party and it is definitely behind the rogue. You also need to drop something else for invisibility sooner. I didn't leave it out. ;-)
You do have every other option on the bards list to select. What you are lacking is more spells known so that you can have them. You are also lacking concentration for a huge selection of them by adding hex. I gave you a good example of a solid spell list. What else are you specifically adding and what are you removing to add it?
Sneak attack needs an ally by the target. Sneak attack is very reliable. Not having it is the exception. The range part is true but the distance can be crossed fast. Range is a definite advantage for the bard.
If the bard has hex on the target and the target has no bonus to the save against fireball and the bard casts spiritual weapon the first round plus eldritch blast, then fireball, then eldritch blast they are very similar from levels 11 through 13, barring a range first strike for the bard or losing hex to fall behind the rogue.
Switching to disintegrate the rogue finally falls behind those high level slots under the same assumptions. Losing hex or giving saving throw bonuses closes that gap. At 20th level the bard has 6 spell slot from 6th level and up to maintain this advantage and does nothing else with those slots.
That's also before adding in death strike or thief's reflexes which slightly favors the rogues again.
No sneak attack req's met and the rogue damage turns into utter garbage. That should clear up the level expectations unless I'm tired and my match is off. It's assuming no save bonus and 65% attack accuracy.
What's sinking your bard concept is the spells apply to 1 out of 3 rounds as damage scales up and those spells don't crit, and TWF sneak attack gives a really high accuracy on the bulk of the rogue's damage, and the sneak attack damage scaling up applies to all 3 rounds of combat in the example.
