There has been some debate about the nature of the D&D end game. When you get from about levels 14-20, and you regularly to fight things that are normally boss monsters in most adventure hardbacks. These include liches, older dragons, and creatures that there are usually only one of.
But how do you keep this whole thing from seeming hokey? Do you simply start making a checklist of monsters of appropriate CR and march them in a procession before your players to have their butts kicked?
The answer to that is no. You shouldn’t just use the monster manual like a who’s who of gradually graded opponents like this is some cartoon of video game. I challenge you* to keep your fights fresh, and try to make them about the narrative, rather than hinging them on numerical calculations.
And this is a lesson that can work from levels 1-20. Combats are so much more than a hit point total and damage output. Work with terrain, hazards, and objects. Your players can’t make use of objects unless you get that ball rolling. Put in a swinging rope bridge that they can affect. Hint at breakable columns that might cause high drama.
The group is likely to break a lot of things, and probably burn what they haven’t broken, but it’s totally worth it when they realize that they have a physics engine** to play around with. Why fight a giant when you can collapse a ruin on it? Or flood it out it’s the 5th labor.
But just so I’m not spewing some old man speech about how you need to do things bigger and better without some kind of prompt, consider the following.
You have a battle in a desert temple. It’s a ruined remnant of an old civilization. Part of that civilization’s fall involved a failed ritual that causes sandstorms at set intervals. Sometimes the sandstorm will bury entire villages, making the entire region nearly impossible to live in.
Now, the temple has been uncovered by a fierce sandstorm for the first time in decades. The group is racing against time, nature, and about two to three other groups to make their way into the temple to retrieve some magical doodad that will help them achieve their next objective.
In this case, the point isn’t so much the destructible terrain as it is the circumstance, though you can certainly play up things like unstable footing, loose walls, and collapsible ceilings. That being said, the objective is two fold; to get to the ruins first, and to get out before the next sandstorm hits. The other groups can serve as complications. They can be undead defenders that have no sense of preservation, or foolish minions that are trying to reach the object before you can. Whatever the case, defeating them may not be the goal, it may even be detrimental to the group’s survival.
So play things like that up. Fighting might not be the answer. Describe perhaps the looking wave of dust on the horizon as the group exchanges blows with their rivals, or the ominous song of the winds whipping through the ruins as the group tries to find the secret entrance.
It might not be an easy task to put a CR on a natural phenomenon like that, but te best part is that you don’t have to. Just figure out the CR of something that would be a tough encounter (usually average level +3) and award them that if they succeed. Heck, reward them some lesser amount if they fail. Unless the group was being unimaginative, the entire endeavor should have been the point of the game, and that right there is worth experience.***
You can use just about any desert temple, but here is one that might make it easier.
* Pun entirely intended.
** In case you don’t know what a physics engine is, it’s basically a way for video games to simulate a world in which objects can interact with the player. Some GMs forget that their worlds don’t need to keep objects static. Heck, I’m guilty of it sometimes too. But really, a good dungeon design considers that the players are in a world that behaves like ours, physics and all.
*** Or you could just… throw like… two golems in the desert ruins. Combat is always still an option too. Just remember to mix it up, keep it fresh. Like maybe the golems are made of ice, and the players have run out of water. Something nifty like that.