D&D 5E Detect Thoughts and Dream Combo

Swedish Chef · Aug 20, 2021

Looking for some input on the above combo of spells.

The PC is thinking of casting Dream on a sleeping character. There would be a savings throw required as per the spell as the target would not be willing.
Then, once in the dream, the PC would control the dream in order to disguise themselves and then cast Detect Thoughts and use the probing feature to try and get some info. This would require a second, different save against the Detect Thoughts.

The conundrum - Detect Thoughts as written has the following caveat "If you probe deeper, the target must make a Wisdom saving throw. If it fails, you gain Insight into its reasoning (if any), its emotional state, and something that looms large in its mind (such as something it worries over, loves, or hates). If it succeeds, the spell ends. Either way, the target knows that you are probing into its mind, and unless you shift your attention to another creature's thoughts, the creature can use its action on its turn to make an Intelligence check contested by your Intelligence check and if it succeeds, the spell ends."

On the one hand, as the DM, I applaud the ingenuity. On the other hand, the bolded text above leads me to believe that the target would still know who exactly cast the spell. The player and I discussed it and decided to throw it out to the EN World crowd and we'd both go with the general consensus.

The last detail - the target would be another PC, not an NPC.

iserith · Aug 20, 2021

It's not clear to me whether one can cast detect thoughts after having entered the trance state that dream brings on, given that it does not allow the messenger to take actions or move. It seems to me the intent of this spell is to send messages at great distances between the messenger and the target or possibly disrupt the target's rest and cause it damage and that's about it.

Detect thoughts also requires the target to be seen and within 30 feet of the caster. If the intent here is to be able to detect thoughts from further away via the dream spell, this also seems questionable if outside that range. Dream doesn't necessarily let you see the target in a way the rules intend. That's a DM call in the end.

In any case, unless you're doing this privately and making whatever saves for the target's player, they are likely to know what's going on anyway. One hopes the target's player is okay with this sort of thing before it's discovered that they are not.

Hawk Diesel · Aug 20, 2021

Yea, I would definitely NOT encourage your player to do this. D&D is a group co-op game. It's not fun to have players who are all supposed to be on the same side to do things that remove agency from someone on the team. I have a strict rule in my games that anytime one player does something that would require any kind of opposed roll from another player (whether that's forcing an opposed check, saving throw, or attack roll), no rolls take place. Instead, player 1 announces their intentions against player 2, and the two players talk about the encounter and come to a consensus on how to resolve the issue or conflict. This may include allowing the roll to go on as normal and decide the outcome, but the important part is that BOTH players agree to this. This allows the group to avoid conflict and for each player to maintain agency over their own characters.

R_J_K75 · Aug 20, 2021

Hawk Diesel said:
I would definitely NOT encourage your player to do this. D&D is a group co-op game. It's not fun to have players who are all supposed to be on the same side to do things that remove agency from someone on the team.

I agree and I've long made a rule in my game that players cannot mind effect, intimidate, or otherwise influence another player. Any attempt to do so simply fails.

iserith said:
It's not clear to me whether one can cast detect thoughts after having entered the trance state that dream brings on

Swedish Chef said:
Then, once in the dream, the PC would control the dream in order to disguise themselves and then cast Detect Thoughts

According to the Dream Spell "While in the trance, the messenger is aware of his or her surroundings, but can't take Actions or move." Detect thoughts has a 1 action casting time so I think no the caster cant cast detect thoughts while in the other PCs dream. Even if did work what's the player hoping to learn that they probably couldn't just ask the other player while they are awake?

turnip_farmer · Aug 20, 2021

Swedish Chef said:
Looking for some input on the above combo of spells.

The PC is thinking of casting Dream on a sleeping character. There would be a savings throw required as per the spell as the target would not be willing.
Then, once in the dream, the PC would control the dream in order to disguise themselves and then cast Detect Thoughts and use the probing feature to try and get some info. This would require a second, different save against the Detect Thoughts.

The conundrum - Detect Thoughts as written has the following caveat "If you probe deeper, the target must make a Wisdom saving throw. If it fails, you gain Insight into its reasoning (if any), its emotional state, and something that looms large in its mind (such as something it worries over, loves, or hates). If it succeeds, the spell ends. Either way, the target knows that you are probing into its mind, and unless you shift your attention to another creature's thoughts, the creature can use its action on its turn to make an Intelligence check contested by your Intelligence check and if it succeeds, the spell ends."

On the one hand, as the DM, I applaud the ingenuity. On the other hand, the bolded text above leads me to believe that the target would still know who exactly cast the spell. The player and I discussed it and decided to throw it out to the EN World crowd and we'd both go with the general consensus.

The last detail - the target would be another PC, not an NPC.

So, as others have pointed out, the plan as outlined is not possible. You can't cast Detect Thoughts while in a dream trance.

If you have an accomplice, you can put them in the Dream trance, and then cast Detect Thoughts. If the targeted player made his save against that spell, I would say that this magical probing alerted their mind and give them an Int check to realise that this is all just a dream (and wake up if they desire).

I'm not really sure what this would all accomplish, though, as our thoughts while dreaming are all jumbled and confused. Unlike others I have no particular compunction against players using mind magic on each other, but it would be up to the dreaming PC to describe the thoughts you detect. Since they're dreaming, I don't see any reason why those thoughts would be coherent or informative.

R_J_K75 · Aug 20, 2021

turnip_farmer said:
I'm not really sure what this would all accomplish, though, as our thoughts while dreaming are all jumbled and confused.

Right. The dream spell itself is odd. I get it you can communicate with a sleeping person across great distances but seems seems like a filler spell for the PHB.

turnip_farmer · Aug 20, 2021

R_J_K75 said:
Right. The dream spell itself is odd. I get it you can communicate with a sleeping person across great distances but seems seems like a filler spell for the PHB.

I think it's there for flavour purposes, but some sorts of players would come up with interesting plans. Hop in the dreams of the evil villain's superstitious sidekick and make him dream omens that imply working with that villain is a bad idea. That could work.

R_J_K75 · Aug 20, 2021

turnip_farmer said:
I think it's there for flavour purposes, but some sorts of players would come up with interesting plans. Hop in the dreams of the evil villain's superstitious sidekick and make him dream omens that imply working with that villain is a bad idea. That could work.

Yeah what I was thinking too. I don't see it being used much by DMs or PCs unless the BBG is some twisted dream weaver.