[5E] Is it OP to upcast Shield to give an ally +5 AC?

[micahaphone]

Shield is a 1st level spell for +5 AC as a reaction. My Abjuration Wizard player wants to use downtime to do magical research, to be able to cast shield onto an ally when they're hit. Is it OP to let this happen with a 2nd level spell slot? He can already RAW use a reaction to throw his arcane ward of quasi-temp hp onto an ally when they get hit, this would just be a different resource and a different way to protect allies.

[JNAProductions]

I'd say it'd need testing, but I'd allow it (with the understanding that if it proves too powerful, it will be void).

But I do like spells and abilities that encourage teamwork, so.

[LibraryOgre]

What range are you thinking? I don't think it's unreasonable as a 2nd level slot, but range should probably be defined.

[heavyfuel]

The ward only works 1/long rest, and doesn't have that much HP.

If the player really wanted, I'd let him research an upcast of 2nd level to protect an ally within 5ft, and an upcast of 3rd level to protect an ally within 30ft.

Still I'd prefer not give Wizards too many tricks

[DeTess]

A piece of 5e homebrew I'm using includes a spell like shield that can be cast on allies within 10 feet, but it only increases AC by 3 (it also gives resistance to one of bludgeoning, piercing or slashing for the rest of the turn though). The wizard in the party has it, and it's definitely a fairly useful spell, but it doesn't seem to be problematic to me.

Using an upcast version of shield with a fairly short range (10 feet is probably a pretty good value) probably shouldn't break anything, but do keep in mind that the impact of shield is often a lot higher on a high-AC frontliner than on a lower AC caster.

[micahaphone]

I like the thought of keeping the range low, maybe 10 ft at second level, an extra 10 ft for every spell level above that. It's a small party, abjuration wizard kobold, helf ancients paladin, and horc 4 elements monk (using a popular homebrew rebalancing version).

Standing within 10 feet of the paladin to make her nigh immortal is a boon and keeps the wizard within her aura of +cha saves/spell resistance, but also puts the wizard on the front lines. To reach the 30 ft range of their 6th level abjuration ward sharing ability, you'd have to use a 4th level slot, which is a big cost.

But if they're already incentivized to hug the paladin thanks to the auras, I'm guessing it'll only be used at the 2nd level slot power most of the time.

[W41Blackr4zr]

I would do something like range of 5-10 ft
and for every spell slot above second you get an extra 5ft