How do I prevent a homebrew Grappling Hook feature from trivializing Tomb of Annihilation?

Question

I am currently running Tomb of Annihilation and letting one of my players play a Revised Artificer homebrew.

One of the features under the Gadgetsmith subclass is a Grappling Hook, with this mechanic:

As an attack or as an action, you may target a surface, object or creature within 20 feet. If the target is Small or Smaller, you can make a Grapple check to pull it to you and Grapple it. Alternatively, if the target is Medium or larger, you can choose to be pulled to it, however, this does not grapple it.

Initially, this is no big deal as the character has weak HP scaling (D8), so it was fine for the player to grapple himself around the battlemap to safety. He then, however, got this upgrade:

Enhanced Grappling Hook:

You enhance your grappling hook, increasing its range to 40 feet. Additionally, the enhanced power of the grappling hook means that when pulling yourself to a larger or larger creature or object, you can drag one medium or smaller willing or grappled creature within 5 feet of you with you.

Emphasis mine. That one clause is beginning to cause a headache for me, as it is a resource free, instant Misty Step + 1 ally to any object within 40ft.

The hook, because he is an Artificer, is magical. It does not operate like a normal grappling hook in that it needs some sort of nook, crack, or lip to hook onto. Instead, imagine a magical magnet that sticks to any object, and pulls you perfectly like the 3-d movement gear from Attack on Titan. The hook is currently incapable of failing, although I am open to nerf suggestions.

I am certain this will break many obstacles in the actual Tomb. To give a few examples:

• 4B - Second Puzzle Door: The player can grapple himself and a companion to the ceiling when the level appears. The pit trap is negated when the lever is pulled.

• 5/5A - Trapped Corridor: Once the player spots or triggers the plates, he can transport the entire party to and from the end of the hallway. Negates the pressure plates trap.

• 15 - Wind Tunnel: The player simply needs to grapple across the tunnel, never activating the fan itself. He can transport the entire party this way. Negates the entire trap.

• 20 - False Tomb: The player can grapple another player out of the room should they trigger the trap. Should he be unable to escape, he can also grapple to the ceiling to increase his survivability against the Wine Weirds. (I actually don't have a problem with the second part of this).

• 37 - Winds of Pandemonium: The player can grapple through the entire length of the room, transporting the entire party across the platforms requiring jumps. Trap is negated.

• 44B - Inside the Vault: The player +1 ally can negate the slippery floor by grappling to the walls or ceiling. This doesn't do much about the Invisible Beholder, however.

• 48 - Shagambi's Tomb: The player can grapple directly to Shagambi's Tomb, eliminating the tip-toeing section of the walk. It negates a lot of the threat in this tomb, although it will trigger 1 sound if he does it optimally.

• Level 5 - Gears of Hate: The player can negate the entire gear experience by grappling to the ceiling, transporting players this way.

I think you get what I'm saying at this point. The hook+1 mechanic is broken when it comes to dealing with a significant portion of the Tomb's obstacles.

There is the option to nerf it entirely and render it unusable in the Tomb; the dungeon does have powerful, world-altering enchantments upon it, so it would not be too out of the box. I am hesitant to do this, however, since the player greatly enjoys grappling around and being mobile.

Overall, my key grievances with this mechanic are this:

• The Grappling Hook is free. It requires no resource usage to transport himself and a companion within 40ft. Compare this to Fly, which also negates a lot of aspects of the Tomb, but is a resource that is used as the player just ferries everyone across/over obstacles.
• There is no check involved. He can bring any willing companion without fail. However, if I were to involve an Athletics check, his character would almost always fail abysmally.
• It works without fail. This aspect, I am fine with and have no desire to nerf.
• It is core to his kit. If I were to take it away, it would crush the player, and I have already allowed it far too long to remove it entirely.

Is there a creative solution/compromise I can bring to this player so that I can make the Tomb experience more gripping and exciting? Or am I blowing out of proportion how good his grappling hook ability is in respect to this adventure?

Answers that cite prior experience with either this module or this/a similar mechanic would be greatly appreciated.

This is the party currently - Gadgetsmith Artificer, Berserker Barbarian, Moon Druid, Shadow Monk, and Clecic 1 Fighter X multiclass.

Answer 1

Your player won't perfectly negate these threats

Yes, your player's PC has an ability that could perfectly negate these traps. However, your player doesn't have perfect knowledge of these traps and can't strategise the way you just did. They don't have the necessary knowledge to fit their grappling hook solution perfectly through the puzzle of these threats.

The player also doesn't have perfect knowledge of the situations you haven't mentioned which, if they use the grappling hook wrong in them, will go badly.

In practice, the group of players will have to discover not only how these traps work, but also take risks that there aren't things they don't know that can still harm them. If they

grapple to the ceiling to deal with the lever appearing there, for a simple example,

they don't know that it's the perfect, simple solution. They will have to consider the room, what they can see, discover, and deduce about it, and make a calculated risk that using the grappling hook in that way is safe.

These risk calculations are the meat and potatoes of dungeons like this. Yes, they have tools which can get them successfully past the threats of the dungeon, but they have to figure out which tools to use, how to use them, and when. The grappling hook is no different from any other tool in that regard.

So to sum:

• Some of these threats will be resolved easily by a combination of the grappling hook and luck in choosing the right way to use the grappling hook.

  That's fine! A particular group will always find some challenges easy and some hard, by virtue of how they decide to tackle it. They'll feel clever and accomplished, which is a large part of the point of being a player in such dungeons.

• Some of these threats will be resolved by the grappling hook, but it won't go easy on the group because they didn't account for a part of the threat, and didn't use the hook in a way that perfectly negates the treat.

  This is also fine. They will learn caution, and that the grappling hook isn't a perfect "win button" for every threat. They'll have to be smart about how they use it.

• Some other threats won't be amenable to solving with the grappling hook, but the players won't be sure about this and may get themselves into trouble trying to solve it that way.

  This is a great way for them to not be sure whether the grappling hook is a good idea for the threats you've itemised, too.

All of that will happen organically. So accept that some of these threats will be nullified during play by the use of the grappling hook, and that will be fun, and that others won't, and that will just be part of the puzzle the players need to deal with — which will be fun.

Answer 2

Tomb Dwarves.

The hook trivializes many of the traps, yes.

The party is not alone in the tomb. Withers can scry the party's movements, direct tomb dwarves and communicate with other legendary monsters, and is not above playing unfair.

Yes, your grappler can get the party, one by one, past many of the traps. And there's a moment there where the party's split in two and only one member can safely move back and forth.

Frankly, I'd be drooling at this opportunity: the tomb and its guardians will make an excellent boss-before-the-boss.

Answer 3

First, I don't think it's really that big a deal. Compare this ability to an innate or easily-activated fly (or in some cases, climb) power plus a rope, or a simple rope with a grappling hook. If the players could get through the trap with relative ease by means of getting a rope from here to there, then this ability isn't really a big deal. Climbing a rope might have a check associated, but you can only make that so hard before it becomes pretty ridiculous. (Examples of characters who could relatively easily run a rope include an aaracokra character, a druid of a certain level, and storm sorcerers, as well as eladrin and anyone with a low-level teleport power, depending on the geometry of the thing.) And anyway, it does take a certain amount of creativity, attention to detail, and presence of mind to pull off these kind of stunts, so to some extent this just feels like rewarding clever play, which is something we should all be trying to do anyway. In a lot of these cases, I'm not sure how obvious it would really be that they can get through by means of the hook, at least until they'd already triggered something and it's too late to bypass the trap with a quick grapple or three.

Second, just because the grappling hook drags you and a buddy from here to there without fail doesn't make it the Hookshot from a Zelda game, where you get to just ignore gravity while you're on it. If he doesn't use it to go up, it should drag him along the floor, which will trigger traps and switches the same as going through at a dead run. He might fly over pit traps, but the idea that he could just whip through without triggering anything strikes me as unlikely.

Third, if it still seems like a problem, yeah, institute an athletics check to bring along a friend, or at least force him to respect his carry capacity. If you can carry a character, then you can bring them along, but (if you'll forgive the metaphor) having a gnomish Luke carrying a dragonborn Leia while swinging across a pit sounds really unlikely to me.

If necessary, raise the roof in some areas to higher than 40 feet to prevent easy access, or make a DM call that a 40 foot hook range is too far and you need to pull it back to 20 or 30 feet (and then similarly push the roof up if necessary). But again, I just tend to make comparison to any number of other mobility enhancing powers and don't think this one is totally absurd.

Another option, if you feel the need to nerf this power, might be to rule that the hook doesn't reset instantly and automatically, but requires some time and effort to reset. If it took, say, one minute of winding to reload the spring to the gadget can fire again, it wouldn't be as viable to rapidly hookshot the whole group around one by one. If it took ten minutes to move the group a mere 40 feet by hookshot, it would be a much less desirable method of travel.

Answer 4

Rebalance the hook

Give the hook a charge system, where it can only bring along a different creature a limited number of times. Let charges recharge during a long rest.

This way, you've given it a resource cost. He can still use it for himself an unlimited amount of times, but if he wants to use it to carry around his party members, he'll only have a limited amount of uses and thus will have to choose wisely when to use it. It also makes sense with the rest of the Gadgetsmith kit, since most other gadgets have a limited number of uses between long rests.

Answer 5

What about covering the ceiling with a Slime or Mold? Even if grappling to move past the trap works the first time it would release a cloud of spores that the player could not move through without risk.

Another option that occurs to me is that it is very difficult to examine an area from 40 feet away. There is no way he can see a tripwire from that distance, for example. It doesn't have to be anything immediately deadly. If he jumps across the trapped area only to get stuck in something like an abandoned spider web that he couldn't see from a distance then he will be much more careful in how he uses the grapple. If he cannot free himself then the rest of the party has to negotiate the traps without his assistance in order to cut him loose.