There are some very sharp contrasts between running adventures below 15th, and running adventures after 15th. Here are a few of the things I've noticed:
- Travel is completely different. When PCs have daily or routine access to teleportation items, plane shift, and eventually gate, travel is no longer an issue. (For example, even if you don't have access to a teleport spell, two plane shifts or two gates can serve the same function! Yes, it takes two higher level spell slots, but these PCs have those slots!) This changes how PCs conceive of an adventure--and certainly how the DM needs to. No longer is distance in any way related to the number of encounters or the time it takes to journey; characters looking at going from their mountain stronghold into a nearby city and characters looking to travel from that same stronghold to a city on a different continent are likely to consider exactly the same magical--and instant--forms of travel to get there. Even if the characters don't know where they want to go, they have access to a whole bevy of new spells (and/or items and/or NPC contacts) who do know: legend lore, scrying, commune, contact other plane, divination, find the path--each offers another window into the unknown, and having access to a combination of them solves a lot of riddles and mysteries without ever leaving home! The end result is that even if they didn't know where they needed a to go, one hint or clue can lead them to the right place to begin their investigations in earnest within perhaps an hour of game-world time. Gone are the early adventuring days where a single clue would form the basis of a month's adventure to a distant hermit to find an answer to a long-forgotten problem.
- Rests are completely different. This is somewhat a corollary to the ideas on travel: because PCs are so incredibly mobile, there are very few times when the right move is not to simply retreat to their magically fortified (and possibly well-staffed) home base whenever they need to rest and recharge. Even if going all the way home is not an option, the PCs may have access to spells or items which are even better than going home. Mordenkainen's Magnificent Mansion (level 8) presents an opulent version of a home away from home, but even a Leomund's Tiny Hut (level 3) can get the job done, offering PCs time to rest and recharge for either a short or a long rest. In addition to the travel changes removing a lot of the "random encounters" on the road, the rest protection options remove many of the dangers of "taking a rest." Only time remains to consistently work against these high level PCs!
- Fights are extremely swingy. High level monsters hit often and they hit hard. High level PCs do the same. Similar to the first few levels of adventuring, it becomes really important that the party tanks (or those with high hp) are taking the hits, while the squishier members of the party are free to control the field or deal damage. Spells that cause an opponent to lose an action or which limit the kind of actions they can take become useful (in my opinion) for the first time. Causing a goblin boss in a low level fight to sacrifice an action is no big deal; an action may have done some damage, but realistically he probably has surrounded himself with a horde of lower level goblins who can deal almost as much damage in a round! On the other hand, causing a dragon, an eight-armed sword-fighter, a high level warlord, or a wizard with 9th level spells to lose an action is tremendous. Each one can do a tremendous amount of damage (or exert a lot of control) in a single round, and forcing a delay tilts the action economy into the hands of the PCs rather nicely. PCs at this level are even more resilient than I had first believed they would be; even when fighting a variety of opponents--each of whom, on their own, would be a worthy challenge for the PCs--the wide range of abilities and synergies the party has access to made them incredibly powerful. The big boss fight at the end of the adventure was spectacular, but when the dust settled, the PCs could probably have done another fight of equal caliber and survived. Then again, it's possible that the PCs could have made one poor choice and the whole fight would have become a rout.
- Even experienced players (and DMs) feel uncertainty. A D&D player from any edition knows what to do when they encounter magic missile, cure light wounds, a locked door, or a new +1 longsword. They've seen all of this before in a dozen, even a hundred iterations. But how many times have players had access to wish? When you're dealing with entirely virgin territory, it's natural for all people involved to feel a bit uncertain. This is both the fun and the terror of the high level campaign. All of my players made some amazing choices and did some epic, heroic feats over the course of the adventure. One that sticks in my mind is when our cleric prayed to his god (Moradin) for intercession to resist the heat of the unholy furnace the party was headed into. Because his character is such a high level, the odds were significantly better than they would have been normally, and a good roll meant that Moradin granted the prayer! The fire resistance the party picked up was (in my opinion) the difference between an easy boss fight and a potentially deadly one. Without a wizard, this party managed to magically solve a problem they didn't legitimately have a spell or a magic item for. That is high level adventuring at its finest.
As this party of characters moves into what will likely be their final adventure together, they're alllevel 18. Those high level abilities most players only dream about their characters having are a reality--or just one or two short levels away. For me, it's going to be a challenge to challenge them. High level encounters each have to be set pieces; no more random bandits or wandering monsters, no more minor problems or careless issues. For these characters to be involved, the threat to the world has to be real, imminent, and disastrous!
And it is.
Stay tuned for more thoughts on high level adventuring as my players take their characters to the brink and maybe a bit beyond!
