Barriers and Obstructions, Tier 3

Previously: Barriers and Obstructions, Tier 2 

Characters: A high-dexterity character proficient in Thieves Tools (+9), possibly a rogue (+14)

Spells (level 6-8): Arcane Gate, Demiplane, Disintegrate, Etherealness, Move Earth, Plane Shift, Reverse Gravity, Teleport, Transport Via Plants, Wind Walk

Magic Items (very rare items awarded): Amulet of the Planes, Boots of Levitation, Carpet of Flying, Cloak of Arachnida, Cloak of the Bat, Ring of Feather Falling, Ring of Free Action, Ring of Telekinesis, Wand of Polymorph, Wings of Flying

Tier 3 (levels 11-16) changes things. By Tier 3, the players will have powers that broadly subvert or circumvent physical spaces. Most conventional physical separations between spaces aren’t even soft barriers anymore. If it could be forced or broken in some way, it wasn’t an obstacle; it was just dungeon dressing. 

Magic items with exploration-relevant traits begin to tail off at this point. The ones that do exist mostly make flight easier and more accessible, but they are no longer giving characters new powers, just decreasing the tax on spell slots and other rest-restricted abilities.

Soft Barriers 

Almost all previous hard barriers. At this point, a conventional door would have to have a DC in the very hard to nearly impossible range (plus Arcane Lock) to even give characters pause. And even then, it would be a soft barrier, not a hard barrier. 

Rogues in Tier 3 begin to break 5E’s bounded accuracy system. As Expertise continues to stretch the top end of their rolls beyond other characters’ ability checks, they gain Reliable Talent, setting a high floor. Assume that if it can be overcome with an ability check, it’s a soft barrier, no matter how imposing.

Magic also takes another leap forward in Tier 3. Etherealness (upcast to target more characters, or combined with a trick like putting the rest of the party in a Portable Hole) can invalidate most conventional barriers. 

Teleport combined with Clairvoyance, Scrying, or similar scouting is reasonably likely to work, assuming the characters are willing to tank damage from a few mishaps. Same with Transport Via Plants, if they can find a plant at their destination.¹

Wind Walk allows an entire group to subvert gaps and chasms, non-airtight collapsed passageways, ventilation systems, and most toxic environments.

Disintegrate and Arcane Gate can make even Wall of Force a soft barrier now, although one with a high resource tax.

Enemy spells. Factions at Tier 3 have serious resources to leverage. If they built or adapted the dungeon, they may employ unusual construction techniques; for example, important rooms may have a thin layer of lead worked into their walls to prevent divination magic from reaching inside. 

Assuming they have access to similarly powerful magic as the PCs do, they will also take full advantage of “location buffing” spells that can be applied permanently or until dispelled. In addition to the usual dungeon denizens and traps, it’s likely that some areas of the dungeon will have a permanent Guards and Wards spell in effect. Note that the discrete effects of Guards and Wards need to be dispelled individually.²

Some areas may be affected by Hallow. Targeting Charisma, a weak saving throw for many classes, this spell can be brutal if used for energy vulnerability in combination with traps, or for the silence function, to ambush spellcasters. A faction willing to spend 1000 GP a pop should absolutely have multiple Hallows up – as long as they don’t overlap with each other – at choke points and laid over other more conventional barriers.

Mordenkainen’s Private Sanctum – at only 4th level – can be cast every day for a year to be permanent without any tangible cost. A faction with the arcane resources and time should absolutely have this spell in effect. If possible, it should be upcast to provide insulation against Dispel Magic and cover a larger area.

Forbiddance covers a huge area and provides multiple layers of protection. Unless the denizens of the dungeon have a particular enemy creature type they already dislike, elemental is a good choice, as characters will often summon them or transform into them. Note that Forbiddance’s components are only consumed on the 30th consecutive day it is cast, so the spell is a cheap 1000 GP. As with other spells mentioned previously, it’s vulnerable to Dispel Magic, so should be upcast when possible.

Symbol is more of a trap than an obstacle, but should be paired with the other spells described herein to build redundant layers of protection. The password feature also does give it some obstacle-like counterplay, where players can benefit from taking the time to learn the password from faction members. As another “until dispelled or triggered” spell, it’s well-suited to dungeon defense.

1 Note that Transport Via Plants only requires that the departure plant be large or larger, not the destination plant. If the lich is surprised when a full adventuring party bursts out of the fern on their desk, they only have themselves to blame.

2 Casting this spell 365 days in a row makes it permanent. Most of the components are trivial, but each casting involves a “small amount” of umber hulk blood. Somewhere in the underdark some duergar are getting rich with their sustainable no-kill umber hulk blood farm.

Hard Barriers

Keyed Planar Travel. Characters have access to Plane Shift, but the spell only allows them to target destinations in very general terms. A faction that wants to allow allies to come and go could have a Teleportation Circle on-site, allowing Teleportation Circle spells (cast from the same plane) and Plane Shift spells (cast from another plane) to send groups directly in. 

This again introduces counterplay, as characters who can find out the sequence have a way in to the dungeon. This begins to stretch the definition of a discrete dungeon, but that’s inevitable in Tier 3 and especially Tier 4 play.

There’s nothing stopping the Teleportation Circle from leading into a dangerous environment. For example, if the faction were all undead, the circle might be located in a chamber filled with field of poisonous gas. A faction could even “let slip” decoy Teleportation Circle sequences; perhaps a Circle drawn upside down on a ceiling above a pit of lava.

Demiplane. For carving out a prison or storage space that is truly difficult to crack. Interestingly, merely knowing the “nature and content” of a particular demiplane is enough for another creature to connect to it – if they also know the spell Demiplane. 

Next: Barriers and Obstructions, Tier 4