Mechanics to represent twin intuition?

Question

I have 2 players who will be playing tabaxi twins, they have a really good backstory and have asked me is there is a way they could have some sort of a link, so if they are not together and one is in trouble the other has a chance of knowing something might be wrong.

I am considering a simple perception check, setting the DC based on events and the strength of emotion the one suffering is feeling. But are there any in game mechanics that could be used to replicate this, am looking for specific rules or feats, low level spells and magic items that I could give the players at level 1 to replicate this.

Answer 1

I have found a few items that do a limited version of what you are looking for, and made a comment about my own experience.

Warding bond (2nd level spell)

This is a second level spell and lets the caster know when the other recipient takes damage, because they feel it too!

This is a very powerful and very risky thing to keep as a permanent effect however, and potentially restricts your ability to create separate adventures should they ever be apart (because one can end up starting a fight almost dead simply because their twin fell off a cliff at the wrong time). The spell has a 60ft range but you can ignore that for this purpose.

Ceremony: Marriage (1st level spell)

Another pretty powerful effect, for 7 days the couple get an AC bonus when in 30ft of each other. This isn't far, but seems to reflect that they are more resilient because of proximity, so that kind of effect could be replicated, and the characters would know when it ends because some bonus stops working (IE: they stop getting that safe feeling).

Sending stones (item). Or the sending spell (3rd level)

The item allows the players to send a 25 word message once per day. Given this is a 3rd level spell it can be quite powerful, but as it is limited to the 2 characters it is less powerful. You could even theoretically limit it to being triggered by certain situations, or let the players trigger it while you decide on the message.

Rule zero

When I did this, so it is not specifically sticking to your criteria, I tied it to 'when it would be fun' which is probably closest to my suggestion of the sending stones above. Basically when I thought I could use the ability to create an interesting narrative I invoked it, but gave the players no control over it because I didn't want them potentially gaming the system, or thinking it gave them permission to split the group.

One example was when one twin received a vision by touching an item, I let the other twin also see the same vision.

This way you have control over how powerful the bond is and how it works. One time they might get an emotion, other times a vision, and sometimes maybe even words, whatever works best for the situation.

Answer 2

Minor frame challenge here. For a vague "my twin is in danger" effect without the chance of deeper communication, I would suggest you both allow it and keep the mechanics very simple - literally just narrate the effect, no rolls or limitations. If one twin's state changes for the worse in some way - starts combat, is trapped, takes damage, is knocked unconscious - then let the other twin know that information.

If you need a rules justification, use this to replace the normal Background benefit trait - which is often something vague and story-driving such as being able to read maps well, find way around a city quickly, or recognition of rank in the armed forces.

It is relatively uncommon that a party splits. In addition, there is an awkward meta-game that turns up when players may know something is up and the players do not have knowledge in character to act. This kind of extra effect can go some way to speeding up the story for these parts, and providing you don't give a massive advantage such as effectively Scrying for free, then there are not really any balance concerns.

In a recent D&D 5E game, my character was knocked unconscious and the remaining PCs fled. The DM ad-libbed that one of the surviving PCs had a vision of my character being carried to another location (actual location and details left vague to keep things interesting). There was no special bond in my case, the DM just picked on the PC that fit the idea of having visions. The outcome was a smoother narrative that continued the adventure well - knowing my character was being moved reduced time spent in the old location. My point being that a similar idea worked just fine without needing mechanics.

If the players are really into the bond and want more tangible benefits, then they may be able to augment it with spells like Message, Sending, divinations, or benefits taken from specific magic items as suggested in other answers. You could grant those as boons or treasure, ideally being even-handed with respect to what any other player characters gain.

Answer 3

For an out of the Ta - box - i solution: GOO Telepathy

This answer is based on applying elements of the Warlock (Great Old One) first level feature to this pair of twins to mechanically represent what you want to do narratively. Give the Awakened Mind feature to your twins as a unique feature for this particular group/campaign.

... the ability to touch the mind{s} of your twin {other creatures}. You can telepathically speak to your twin {any creature you can see} when they are within 30 feet of you.

What's in brackets is from the PHB and removed as an edit to hack this feature in order to arrive at a unique way to represent the connection that the twins share.
The result is, for each of their PCs:

... you have the ability to touch the mind of your twin. You can telepathically speak to your twin when they are within 30 feet of you. (If you think that increasing the range increases the fun, by all means toggle it up and down until you hit a sweet spot).

My experience with this is more from RL than 'in game' but it was uncanny. When I was in 7th and 8th grade a pair of identical twins were my classmates. Marvin and Kevin. It was eerie how, it seemed to me, the two of them were almost completely in tune with one another

As a sub class feature, it's not particularly powerful, but my brief experience with this feature, as a low level GOO Warlock, was that it was quite handy in some situations (scouting areound corners in a dungeon, and trying to set up a scam on a corrupt village headman). You aren't breaking any balance concerns if you implement this for this pair of twins. Not to mention:
Rule of Fun is a fine approach to take. 😀

You can implement this at character creation as a custom background feature for each PC (replacing the other background feature) per @NeilSlater's excellent answer.

Answer 4

The "Telepathic" feat (Tasha's Cauldron of Everything) has as one of its three features:

You can speak telepathically to any creature you can see within 60 feet of you. Your telepathic utterances are in a language you know, and the creature understands you only if it knows that language. Your communication doesn’t give the creature the ability to respond to you telepathically

represents an option available to all characters regardless of class, but would normally only come online at level 4 for Tabaxi. It does share the range limitation common to suggestions in other answers.

If you dont want to give a free feat at level one, you have a few options:

• Sticking to pure RAW, You could use the optional rules for creating a race to create a custom race that is a close relative of the tabaxi, which would let them start the game at level 1 with the feat (but they'd lose the other Tabaxi traits)

• As DM, you could probably just give them this one part of the feat at level 1 (possibly limited to only their twin, possibly requiring them to actually take the feat to replace their first ASI)

If they do take the full feat at some point, I'd personally handwave the range limitation for communication between the twins only, unless they were obviously powergaming it. If they're each telepathic with everyone, I'd want the connection between them needs to be differentiated somehow in order to remain special (although the feat does usually only allow one way communication, the fact they can undetectably communicate both ways may feel special enough to you and your players, talk it over with them if you go this route).

This wouldn't directly allow them to sense the other's emotions, pain, or danger level, but its easy to set up a system that gives that effect: "Whenever we're separated, Twin A calls "Marco" every hour (or every minute if were on high alert or suspect danger) and Twin B responds with "Polo". If either fails to call for any reason, we know something is very wrong".

Answer 5

Enhance the tools they already have.

Depending on what tools they have available to them already, an interesting solution might be to waive the range/sight limit when targeting each other with non-touch effects.

This means for example, if they have the Message spell or a short-range Telepathy or even the Insight skill, they can use those features on each other regardless of distance or intervening obstacles, but they'd still have to spend the usual cost to do so (if any).

If they have the Scrying spell, it would still cost the spell slot as usual, but you might allow them to auto-fail the save even if they are unaware of the spell being cast.

You might want to limit this to Divination effects or otherwise "non-physical" effects, otherwise it would apply to Dispel Magic or Shield of Faith, but then you might decide to allow that because it sounds kind of cool. You might decide to allow it with touch spells or even self-only spells, if you really want to run with it. Perhaps you could even grant these additional benefits over time, to represent their bond strengthening as they gain experience or whatever.