Sounds good, let's do an underbar psionic variant when we get this done.
Agreed.
So, assuming that ESP back in 1998 was telepathy, we can leave that off. Your spell selection looks fine.
In First Edition AD&D
ESP was a 2nd level magic-user spell that was basically a low-level version of
telepathy that was only able to detect "surface thought" of a creature. The spell description is rather vague:
Explanation/Description: When an ESP spell is used, the caster is able to detect the surface thoughts of any creature in range — except creatures with no mind (as we know it), such as all of the undead. The ESP is stopped by 2 or more feet of rock, 2 inches of any metal other than lead, or a thin sheet of lead foil. The magic-user employing the spell is able to probe the surface thoughts of 1 creature per turn, getting simple instinctual thoughts from lower order creatures. Probes can continue on the same creature from round to round. The caster can use the spell to help determine if some creature lurks behind a door, for example, but the ESP will not always reveal what sort of creature it is. The material component of this spell is a copper piece.
There's also a psionic version:
This discipline allows the user to "tune in" to the unshielded thoughs of the minds of any creatures within range when the power is employed. In most respects it is identical to the magic-user spell, ESP (q.v.). Thoughts received in non-understood languages will be meaningless. Non-intelligent creatures will transmit "pictures" or raw drives.
Notice it adds the interesting wrinkle that it doesn't breach the language barrier, so if you read the mind of an orc who's thinking in Orcish a MU who doesn't speak that language won't understand the surface thoughts. Back when I actually ran 1E I tended to rule it's possible to gauge the creature's state of mind- angry, lustful, bored, et cetera - by the tone of their "mental voice". Not that PCs used it very often.
In my experience, it suffers from the "Deanna Troi" issue and only reveals surface thoughts that are blatantly obvious from the context of an encounter: the wizard furrows their brow and declares "I sense hostility ahead!" as a rabid troll leaps out of the darkness and starts ripping up the lead fighter.
It's also got a relatively short range (60 feet) so isn't much use for "scouting out" whether there are any creatures ahead of you. The psionic version's range is 50% longer, for what it's worth.
The 2E
Player's Handbook description is a bit more elaborate:
When an ESP spell is used, the caster is able to detect the surface thoughts of any creatures in range—except for those of undead and creatures without minds (as we know them). The ESP is stopped by 2 feet of rock, 2 inches of any metal other than lead, or a thin sheet of lead foil.
The wizard employing the spell is able to probe the surface thoughts of one creature per round, getting simple instinctual thoughts from lower order creatures. Probes can continue on the same creature from round to round or can move on to other creatures. The caster can use the spell to help determine if a creature lurks behind a door, for example, but the ESP does not always reveal what sort of creature it is. If used as part of a program of interrogation, an intelligent and wary subject receives an initial saving throw. If successful, the creature successfully resists and the spell reveals no additional information. If the saving throw is failed, the caster may learn additional information, according to the DM's ruling. The creature's Wisdom adjustment applies, as may additional bonuses up to +4, based on the sensitivity of the information sought.
The material component of this spell is a copper piece.
Not entirely sure how that applies to the Slaiyith. I guess they might have ESP telepathy that doesn't include transcending language restriction, and since they can only speak Slaiyith and Valgoss they're can't normally talk with it.
Or maybe they're just mentally incomprehensible to humanoids. There are creatures like that in D&D.
