Barriers and Obstructions, Tier 2

Previously: Barriers and Obstructions, Tier 1

Characters: A high-dexterity character proficient in Thieves Tools (+8), possibly a rogue with Expertise (+12); a high-strength character (+4); potentially a monk with the improved Unarmored Movement feature, a druid with the ability to wild shape into a creature with a flying speed, or a cleric with the Divine Intervention feature

Spells (level 3-5): Dispel Magic, Dimension Door, Fly, Freedom of Movement, Gaseous Form, Meld Into Stone, Passwall, Polymorph, Stone Shape, Tree Stride, Water Breathing, Water Walk

Magic Items (rare items awarded, uncommon items more widely available): Boots of Striding and Springing, Boots of the Winterlands, Broom of Flying, Chime of Opening, Folding Boat, Gloves of Swimming and Climbing, Gloves of Thievery, Necklace of Adaptation, Oil of Etherealness, Potion of Gaseous Form, Quaal’s Feather Token (Swan Boat), Ring of Jumping, Ring of Warmth, Ring of Water Walking, Slippers of Spider Climbing, Winged Boots

Soft Barriers

Locked, stuck, and barred doors of any material, as well as most Arcane Lock doors. In Tier 2 play, rogue expertise starts to push their key skills into the double digits, and they’ll begin to break free from 5E’s bounded accuracy system. Magical items like gloves of thievery, as well as the prevalence of spells like Guidance, will generate ability check results in the 20s and 30s more and more frequently. Groups without a rogue are increasingly likely to have spells or magic items that trivialize conventional doors. Arcane Lock doors remain harder to crack, but will no longer represent a hard barrier as they did in Tier 1.

Dispel Magic is available to almost all groups beginning with Tier 2. Dispel magic is potent in its broad language (there are few limitations on the “magical effects” it can target) and it will quickly become a go-to solution for parties that appreciate its potency (in my game, the party often had two or even three casters with the spell prepped at any given time).

Note that Arcane Lock can be cast with a higher level slot. Arcane Lock itself doesn’t gain anything by being upcast, but spells like Counterspell and Dispel Magic calculate the DC based on the spell slot actually used to cast Arcane Lock, not its minimum spell level. So, for example, in a dungeon run by an Arcanoloth that knows the spell Arcane Lock and has had ample time to prepare, assume that it has cast those Arcane Locks, once per day, with its 8th level slot, for a DC 18 to dispel. Factions savvy to the ways of magic will always cast Arcane Lock with the highest level spell slot available for this reason.

Also note that these soft barriers are still a meaningful tax on the characters’ resources. An area with a series of hallways or cluster of rooms with high-DC doors plus Arcane Lock may not present a hard barrier to the characters, but they may need to make several trips to the area to fully explore it, during which time local factions can respond to their intrusions.

Water, climbs, and gaps of any length. The solutions will vary greatly from party to party, but solutions they will have in Tier 2. Flight becomes increasingly accessible. Water walk and water breathing are both ritual spells affecting up to 10 creatures; once a character commits to the spells-known tax of acquiring these, it’s easy to make them always-on abilities for the characters (unless, of course, an enemy casts Dispel Magic on them). Features like water and verticality like climbs and pits are still good soft barriers to introduce as redundant complications with other effects, but they won’t gate the players progress in a meaningful way, as they did at Tier 1.

Extreme temperature, gas, and pervasive environmental conditions. The characters now have enough spells, HP, magic items, and other countermeasures to reasonably tackle these areas.

Illusions. Spells like Hallucinatory Terrain, Mirage Arcana, and Programmable Illusion are soft barriers, as they can always be investigated and penetrated, but they’re easy to deploy and combine well with other types of soft barriers. Nystul’s Magic Aura, for a mere 2nd level slot, can be cast daily for a month to permanently hide a magical aura, or provide a fake aura for something non magical. This is an easy way to help hide magical traps, or provide red herring and false treasure to lure characters into ambushes and hazards.

Most magical walls; Blade Barrier. Dispel Magic opens up doors, literally and figuratively. As with Arcane Lock above, it’s reasonable to assume that magical walls were upcast to make them resistant to Dispel Magic; but even with a higher DC, these spells will delay, not stop, persistent characters. At Tier 2, it’s also increasingly practical to just tank the damage. This approach is fine, insofar as it also creates an interesting compilation if the characters try to come back the same way, perhaps fleeing a dangerous enemy.

Hard Barriers

Hard barriers in Tier 2 become more complex, and writers should be sure to provide consistent description and mechanical support to these barriers, so that the DM can adjudicate the players’ many options for piercing them, and the players can understand that the consistent and fair logic to the dungeon space, even as challenges scale up.

Password-protected or airlock “doors.” “Door” is in quotes here because for an aperture to represent a hard barrier at Tier 2, it needs to hide or heavily shield the point of transition between zones, like a prison or military facility would. The “door” functions more like a wall except under very controlled circumstances. The opening mechanism is probably separated from the aperture it controls. Passwords or puzzles may be applied. One or both of the opening mechanism and the aperture may be well-hidden or physically distant from each other.

Dungeon factions with reasonable resources also won’t just employ a single layer of defense. They will expect that their outer layer of security will sometimes be breached, and have a “defense in depth” prepared to respond to excursions.

For example, members of a faction traversing a particular secure door might have two keys; one to unlock the door, and one to deactivate a hidden mechanical timer on the far side of the door. If someone breaches the door, but fails to key or disarm this mechanical timer, it will trigger a breach protocol that causes subsequent sections to seal shut with mechanical or magical bulkheads or similar defenses.

This sort of alarm could be associated with any other number of conditions, triggers, alarms, dead man switches, and so forth. The DM should simply ensure that it's at least possible to locate this kind of redundant security, either through careful investigation, contextual clues elsewhere in the dungeon, faction interrogation, alliances with friendly or neutral creatures, etc. Hard barriers, not impenetrable ones.

Exotic and magical doors. Doors imbued with an Antimagic Field, doors that regenerate from damage, doors that change destinations if opened without the key; Tier 2 opens the door (ha ha) to all this and more. When deploying doors with bespoke, homebrewed “trick” effects, the DM should have a clear understanding of the limits of the door’s magic and give the characters clear information, so they can make informed decisions.

Exotic environmental conditions. Expanses of lava and lakes of acid can generally stop Tier 2 characters, just as more mundane conditions stopped them at Tier 1. Again, it may be worth considering complications that might arise from the one or two most common gambits players employ. How hot is the air above the lava pit? Does it ignite ropes? Can the characters fly over the acid lake, or do sulfuric fumes threaten to incapacitate them?

Reasonably thick walls of stone, metal, or similarly durable material. Dirt is no longer much of an obstacle, but stone and metal will generally still stop Tier 2 characters. The cracks begin to show if characters go for certain spells.

Stone Shape can create a permanent doorway, but only 5’ deep. Meld Into Stone can be cast as a ritual and lasts 8 hours (!) but only affects the caster. This could facilitate scouting, or deal with obstructions secured from the opposite side. Particularly savvy enemies composing a dungeon from scratch (rather than improving or adapting a natural or conventional space) could leave gaps of non-stone material interspersed within all stone bodies such that a melded character couldn’t move through them.

Passwall comes at the high cost of a 5th level slot, but can allow an entire party to move up to 20’ through a variety of surfaces without issue (although they only have an hour to come back the same way). This is another instance where a group willing to invest the resources to break a hard barrier can be rewarded without reservation.

Wall of Force. Wall of Force is specifically immune to Dispel Magic. That makes it a powerful hard barrier for Tier 2 characters, with a few interesting exceptions. Dimension Door can take the caster plus one passenger through a Wall of Force, but they need to either see their landing spot, or be able to reasonably guess where it is. If whoever put the Wall of Force in place was particularly crafty, they might have set it up with no visible landing spot on the other side (because it faces a vertical shaft or a chasm, with a ledge out of view, or perhaps an invisible walkway).

Certainly, Tier 2 characters could use Clairvoyance or similar scouting tools to find a Dimension Door target; but that level of resource investment and work is within the bounds of what we want for breaking hard barriers.

On/Off “Switch” Teleportation Circles. Teleportation Circles present an interesting option as a hard barrier. The spell language indicates that "Any creature that enters the portal instantly appears within 5 feet of the destination circle or in the nearest unoccupied space if that space is occupied" (emphasis mine). There is no maximum limit to the displacement one can create.

Imagine a teleportation circle on a platform surrounded by some serious dungeon hazard. If an alarm has been raised – or perhaps if the teleportee merely fails to “radio” ahead with some predetermined signal – a large stone block the size of the platform can be lowered to cover the circle. Arrivals now appear in the nearest unoccupied space (thin air off to the side of the now-obstructed platform), dropping into the (acid? Lava? Bottomless pit?) below. As always, this should not be a “gotcha” used punitively; the hazard on the receiving end should be survivable, and (or) the players should have ample opportunity to learn about the danger before risking it.

Teleportation pads. This is a staple of old-school D&D and many video games, appropriate for high magic settings. Two-way pads can function something like Teleportation Circles, perhaps with a cooldown between uses. One-way pads blur the line between obstructions and traps, but present an interesting complicating factor for the characters. Again, the DM should have a clear understanding of how these work, and to what degree they do or do not mimic other spells or effects, so players can (through trial and error, or experimentation) learn from the obstacle, and perhaps even exploit it.

Next: Barriers and Obstructions, Tier 3