Is this houserule for upcasting Haste balanced?

Question

Haste is a great spell. I want to make it better at the cost of higher spell slots. Additions to the spell description will be added in italics (except 3rd-level transmutation since the book puts that part in italics).

HASTE
3rd-level transmutation

Casting time: 1 Action
Range: 30 ft
Components: V, S, M (a twizzler)
Duration: Concentration, up to 1 minute

Choose a willing creature that you can see within range. Until the spell ends, the target's speed is doubled, it gains a +2 bonus to AC, it has advantage on Dexterity saving throws, and it gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.

When the spell ends, the target can't move or take actions until after its next turn, as a wave of lethargy sweeps over it.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you can choose one of these additional effects for each slot level above 3rd (each option can be chosen only once):

• The target's speed is tripled, instead of doubled, for the duration.
• The target gains a +3 bonus to AC, instead of +2, for the duration.
• If the target has a feature, such as Extra Attack, that allows it to make more than one weapon attack with a single Attack action, it may make up to two weapon attacks, instead of the usual one weapon attack, with the additional action granted by this spell.

For each additional effect chosen, the target cannot move or take actions for an additional turn after the spell ends.

Obviously this makes haste better. But I'm not sure how much better. The +3 to AC could start to push bounded accuracy off the table when combo'd with spells like shield of faith or a build that already optimizes for AC. Basically, there are obvious combos where upcasting in this way can amplify the already brokenness of those combos, but I don't think it should be much of an issue for most normal use. But just in case, I added the clause at the end to increase the risk of upcasting this. For each additional effect chosen, the wave of lethargy effect increases by a turn. So casting this at 6th level and choosing all three effects means the target is out for four turns when the spell ends.

Some other options to consider for balancing would be to require two extra levels of spell slot for each effect, so getting an extra effect at 5th, 7th, and 9th levels, or having the extra effects kick in when cast at 5th level or higher and requiring 1 extra level per effect, so getting an extra effect at 5th, 6th, and 7th levels. Reviewers that deem this unbalanced as written should consider these changes to slot level for balancing.

Is this addition balanced?

Answer 1

Balanced, Maybe Underpowered

Greater Invisibility is a fourth level spell. This allows you (for the same duration and concentration as your 4th level Haste) to get advantage on attacks and disadvantage on being attacked against most enemies. Advantage/disadvantage is roughly equivalent to a plus or minus 5, respectively. So Greater Invisibility is better defensively, and typically better offensively (+5 to hit is probably worth trading that one attack, especially if one as Great Weapon Master or Sharpshooter). Greater Invisibility also doesn't leave you actionless for several rounds! Unless my enemy has some way to see invisible creatures, the only way I'd think about casting this Haste at higher than 3rd level is if my target already had Greater Invisibility.

Now, that doesn't mean this doesn't work in certain scenarios. If you really need move speed, but also want combat capability, this is nice (if you need to race you are probably better off with Dimension Door, also at fourth level). This can also be nice if you are able to stack buffs on the target. So it's *usable*, and since it's not taking an extra prepared slot, it seems like a nice inclusion. I wouldn't expect it to be used much compared to other 4th level spells, since the increasing cost (a round of boring) is not really worth the incremental benefit in most cases.

Answer 2

No. This is not balanced.

Haste gives double speed, +2 AC and +1 attacks. That makes it pretty good. +2 AC is par with Shield of Faith, a level 1 spell. Doubled speed is slightly better than Expeditious Retreat, a level 1 spell. An extra attack from a fighter can deal on average, with a greatsword, 12 damage. The fighter will probably get to use it 3 times, for 36 damage, which is about par with a 3rd level damaging spell that targets one creature (see dmg page 284). This makes it quite a strong spell.

In contrast, your upcast version makes it a significantly better shield of faith, probably a second level spell, a extremely better expeditious retreat, probably second or maybe a third level spell, and 72 extra damage over 3 turns, which is the equivalent of an 8th or 9th level spell damage from an attack spell targeting one creature (dmg page 284). It is clear from this that the only really good option is the two extra attacks. In addition, you have to keep in mind that upcast spells are supposed to be slightly worse the normal spells of their level.

This is not balanced. You could make it balanced by making it an 8th level spell, or removing the extra extra attack option.

Even though it says that the creature must have extra attack to gain the two additional attacks, it still is not balanced because by the time you have 4th level spells, the person you are casting the spell on will have extra attack.

Answer 3

Even if it were balanced, it's unusual

Your homebrew effects are as wordy as the original effect. It's complicated, and dynamic, and adds flexibility to a spell in a way that most spells don't get.

Many spells do not get better effects when upcast, but those that do just increase the damage, or the number of targets, or otherwise fiddle with one number at most.

I would recommend just increasing the number of targets you could choose with the spell by 1 for every two levels it's cast above 3rd level.

Short, sweet, and effective.

Answer 4

The downside is too strong

This answer is coming from someone with the controversial opinion that haste is a terrible waste of a spell slot (unless for some reason moving really quickly is important, and even then expedient retreat potentially covers that for the wizard).

I already refuse to cast haste as a wizard, or have it cast on me as a melee character because spending a round stunned in combat is a price that I find far too steep.

Using the standard spell; for the cost of an action and concentration (caster) you are giving a fighter maybe a 33% damage increase (Lets assume 1d10+5, so around 11 damage per round). That damage increase is less if your fighter is already dual wielding.

Instead your wizard could cast slow, with a significant chance of having a massive effect on combat and a vastly reduced amount of incoming damage. Or they could cast fireball, and lets assume the average combat lasts 3 rounds they only need to hit 3-4 targets to cause as much extra damage as that hasted attack will over the course of the full combat, and fireball doesn't take concentration - plus frontloaded damage can take out the minions faster which reduces incoming damage and makes the adventuring day easier because less hit dice and less healing spells are needed).

However your fighter is now incredibly vulnerable because your squishy wizard with potentially 13 AC just needs an arrow fired at him to disable them for a round. Losing that round once every few fights actually decreases efficiency despite the hasted action, and that isn't even counting the opportunity cost of the wizard picking fireball, or the cleric casting better spells because they no longer have to keep slots to heal people.

You are giving pretty small advantages (yes it might push bounded accuracy, but on a player already pushing those boundaries the real issue is the player not your spell), and doubling that downside.

Adding the extra attack is potentially useful, but again at 4th level you could polymorph someone into a t-rex and not only save incoming damage (allowing your cleric to blast or disable enemies instead of healing), but that t-rex is causing all sorts of damage and panic in the enemy ranks. You could also upcast fireball, again only needing to hit 3-4 enemies to cause roughly the same amount of damage.

I would say that if you like haste, then this probably feels as balanced as haste does, but I would also say that if you like haste then balance isn't actually what you are looking for.

To 'fix' it?

As I said your upcasting options are not as powerful as you think, they are in keeping with the theme and basic power level of the spell, but your downside is too much. I would just keep the single round, keep the same upcast options, and call it ready for playtesting.

Side note

The best use of haste (imho), giving a rogue an extra chance to sneak attack with a held action, is not going to be buffed at all by upcasting because even if they could use 2 attacks on that held action via the spell, they only sneak attack on one.