What happens if I let my conjuration wizard be able to target unwilling creatures with Benign Transposition?

Question

The 6th level conjuration wizard feature Benign Transportation says:

Starting at 6th level, you can use your action to teleport up to 30 feet to an unoccupied space that you can see. Alternatively, you can choose a space within range that is occupied by a Small or Medium creature. If that creature is willing, you both teleport, swapping places.

Once you use this feature, you can't use it again until you finish a long rest or you cast a conjuration spell of 1st level or higher.

My plan is to make this able to work on unwilling creatures as well. They get to do a Charisma saving throw and if they succeed, they are unaffected.

Would this be game-breaking or abusable?

Answer 1

Likely to be game breakingly powerful with a clever player.

tl;dr The ability allows the character to easily use the environment to overcome foes. This will likely make the game less fun for other players.

Environmental hazards are a staple of adventurer lives and encounters.

The ability to move a creature 30 feet after every conjuration spell (L1 or greater) is cast will likely give the wizard at least 3 uses per day. Expect a clever player to get many more uses per day as there are ways of casting spells without using spell slots.

The prevalence of environmental hazards; cliffs, gorges, holes, lava, magma, spikes, deep water, fast moving water, deep lava, fast moving lava, portals, rifts, ramparts, haphazardly strewn about children's toys, etc; cannot be understated.

A clever player with the ability to teleport the high strength, constitution, or dexterity opponents, which usually lack a high charisma, into potentially lethal environmental hazards should make many confrontations dramatically easier.

Risk overshadowing other player's characters.

The real risk here is the reduction in fun for other players. A character that can often obviate or eliminate a powerful opponent without much help from the other characters often sucks the fun right out of the game for the others. They become side kicks instead of co-equal party members.

Answer 2

It can become powerful in the right situations

Wizards get the Fly spell and that alone, mixed with your suggestion, allow for a lot of powerful combinations - mostly based around the Wizard positioning themselves over a cliff, lava pool or similar dangerous natural obstacle and then switching with an unwilling enemy and letting gravity do its thing.

Or it could be used to place an enemy is a seriously disadvantageous position through moving into a tight corner or surrounding yourself with your allies and then switching, leaving the enemy attacked from all sides.

I'm sure if you allowed this the players would come up with a variety of tactics you hadn't considered that may or may not break your combats.

But, having a Charisma save weakens it somewhat and being unable to switch with creatures sized Large and over is quite a limitation as well, as is the range (a relatively small 30 feet), so the fun side of me is thinking "Do it!".

Just be prepared for some situations to be ruined in ways you didn't foresee.

Answer 3

Likely, not much. (Some hilarity may ensue)

As other answers noted, moving an opponent into an environmental hazard is powerful. However, there are a few aspects counteracting this.

• First, as Steve points out, the wizard and the opponent swap places, so the wizard needs to get near that hazard himself first, e.g., by flying over that pool of lava before not-so benignly swapping places with the opponent. As the GM, make sure to graphically describe the hazard, and request that concentration check as the flames lick at the wizard's robes. We would hate for him to lose concentration on his fly spell and fall into the flames right before he does the swapping, wouldn't we? (So smart wizards will use a deep pit, rather than lava.)

• Second, same point: as soon as the wizard moves voluntarily into a hazardous situation, smart enemies take note. They may read RPG.SE, too. So if the wizard is setting this trap up, the enemy may notice and concentrate their fire on him. (Even if he flies over a pit without lava, some damage may make him lose his concentration). Especially if the wizard makes this a common method.

• Third, again, same point: the wizard and the opponent swap places. Yes, the opponent is suddenly surrounded by the wizard's friends, who proceed to beat him up. However, at the same time, the wizard is surrounded by the opponent's friends. The kind of opponent this works on (low CHA, higher STR, DEX, CON) can take a lot more close range beating up than a wizard. It would work on opponents that have no friends, though. Pick your enemies wisely.

• Finally, this is quite short range, at 30ft. (The description is not clear on whether this swapping also uses the 30ft range, but I'll assume it does.) So the wizard first of all needs to get close enough to an opponent and into the kind of hazardous situation where a swap would make sense. Wizards that are within 30ft of BBEGs get squished quickly, even with friends around.

Honestly, this looks like a rather high risk proposition for the wizard, so I would be less apprehensive about allowing it.

Finally, another way of weakening it would be to let the unwilling opponent do a CHA saving throw. If they succeed, the opponent does not move... but the wizard gets teleported up close to the opponent.