[RPG] Can a Wizard polymorph low-level PCs into over-powered beasts

dnd-5epolymorphspells

According to Polymorph's description,

The new form
can be any beast whose challenge rating is equal to or
less than the target’s (or the target’s level, if it doesn't
have a challenge rating).

For example, a Tyrannosaurus Rex (MM, p81) is a beast with CR 8, 136HP, multi-attack, +10 attack modifier and a lot of damage.

Can a Wizard, at level 8, cast Polymorph on another PC (also at level 8) and turn him into a Tyrannosaurus Rex?

This sounds awfully broken. CR is usually measured against party level. A CR 8 enemy is meant to be a decent threat to a party of 4-5 PCs of level 8. We could find a ratio here, where each player accounted for 2CR (sort of…). But Polymorph lets one of the players actually equally face an enemy that could challenge the entire party.

I realize that there aren't any stronger beasts than the T-Rex, so the power-level doesn't grow, but it still feels like a spell that can easily break encounters. E.g., big boss fight incoming, some big baddie with a couple of helpers. The Wizards turns the out-of-spell-slots Bard into a T-Rex and then hides behind a pillar and inside a Minor Illusion Box. The T-Bard wrecks havoc among enemies while the party supports him and the Wizard is smoking his pipe hoping no one remembers he exists.

Best Answer

Yes.

This may seem overpowered but there are several drawbacks to the spell:

The target's game statistics, including mental ability scores, are replaced by the statistics of the chosen beast. It retains its alignment and personality.

If you transform them into a T-Rex they become an unintelligent beast with an INT score of 2.

The creature is limited in the actions it can perform by the nature of its new form, and it can't speak, cast spells, or take any other action that requires hands or speech.

It can't communicate with you while in its new form or use its hands to activate any items, or otherwise perform any task that requires hands or speech.

The target's gear melds into the new form. The creature can't activate, use, wield, or otherwise benefit from any of its equipment.

It's AC changes to 13 (T-Rex is easy to hit but not easy to kill) making it an easy target from long range. It can't benefit from any magic items it might have or any armor or shields.

Also, the spell requires concentration. This carries two more drawbacks.

If the caster takes damage he or she must make a concentration check to maintain concentration. If it fails, the target reverts form which could potentially put them in a very bad situation, surrounded by enemies and perhaps with low HP (maybe polymorph was cast on the fighter when he was almost out of his own HP).

The other drawback here is the opportunity cost of concentration. The caster can't concentrate on any other spells while he is concentrating on polymorph, which means any other spells available to the caster that require concentration aren't available for the duration. This is a spell list that includes things like hold person, fear, suggestion, haste, slow, wall of fire, web, invisibility, greater invisibility, and levitate, to name only a handful of the concentration spells available to a level 7 wizard.

Consider also that beyond class level 7, there would be even more concentration spells available which might come at a higher opportunity cost than polymorph.

Furthermore, there is also the opportunity cost of learning polymorph. When you first gain access to it at level 7 as a wizard or sorcerer, you have 1 (sorcerer, bard) or 2 (wizard) spell choices available. Druid gets it automatically as they know all their spells -- crazy, right?

As a bard or a sorcerer at that level, you have chosen to forgo all other level 4 spells so that you can transform something into a T-Rex for one hour once a day (maybe more if you spend sorcery points). As a wizard, you have a little more flexibility. In any case, the opportunity cost of choosing this spell over any other spell should come with an appropriate value -- in this case, the ability to temporarily transform someone into a powerful beast and the versatility of being able to transform them into any other less powerful beast.

However, I think you're overlooking the more powerful use of polymorph -- the potential of turning any opponent of yours into a harmless chicken or goat while you take care of the rest of the goons trying to steal your gold. Removing a single powerful enemy from combat is a much better use of your action than creating a powerful ally, when creating a T-Rex leaves the powerful enemy on the table to make attacks against you and your other party members.