I'm going to set up a hypothetical scenario.  I've made a traditional JRPG.  The first part of the game is a pretty linear affair.  Of course because this is a JRPG there are levels to gain, equipment to buy, and spells to learn.  Through this linear section the game's difficulty ramps up at a steady pace with the player's level.

There comes a point near the end of the game where the world "opens up."  The player has the choice to go straight to the final dungeon and complete the game OR complete the dozens of side quests that are available.  Of course these side quests have rewards for the player such as more powerful weapons, equipment, and spells.

Now I have a dilemma.  One player could skip all the side quests and go straight to the final dungeon.  Another player could complete all of the side quests before attacking the final dungeon.  These two players would have a massive difference in power levels. 

How do I balance the final dungeon so that both players get an adequate challenge?

Do you actually need to make it dynamic for the game to be fun?

If I want to run directly to the final boss's lair as a challenge, is there a reason to prevent it?  As a timely example, there are speedrun players for Zelda Breath of the Wild who never pick up armor or shrines or side quests beyond what is required to get down off the initial plateau, and head directly to defeat Ganon still dressed in starting clothing, having only three heart containers, and carrying only the crappy weapons picked up along the way.

On the other hand, if you want to grind and get your character up to level 999, is there a reason to make the final boss so much harder? If the player has advanced their character to the point where they're basically godlike power, why should every monster in the game also be boosted to epic power levels?

A fixed power level is often good because it feels most natural to the player. If I'm a wimp and I face the boss I know I'm underpowered. If I'm maxed out the final fight better be easy, because I'm completely overpowered.

There are some game designs where dynamic power levels are important, but often it introduces terrible problems on the extremes.  Speed run players in a dynamic power system may find the final boss trivially easy to beat, and 100%'ers find the dynamic power system makes success nearly impossible.

Those are great points Frob.  Thanks for the input.

If the content does scale with the player, it doesn't have to scale 1:1 with them. For example, it your combat features a combo system, it wouldn't be fun if the player becomes so powerful that they one-shot everyone and can't use combos anymore. In that case it would make sense to buff the enemies a little: make them tough enough that the combos are still needed, but weak enough to still allow the player to wipe the floor with them.

Similarly in a traditional JRPG: if the player grinds up levels so high that the first attack of the first turn wipes all the enemies, that's just not fun, even for fans of power-leveling. But if the new enemies can last a couple turns against the party, but still go down quickly, that allows the power-leveled player to unleash all the moves that they grinded for, which causes more satisfaction.

Scaling content with player level defeats the point of having player levels in the first place.

Ask yourself: does this game need player levels?  Do they have an actual reason for being in the game, other than that that's what other games do?  What do they add to the game?  What are the drawbacks of player levels?  Are the advantages of having player levels enough to offset the disadvantages?

Then decide to either include player levels in the game or not.  But don't take the half-assed approach of including player levels but also scaling the power of the enemies.  That just turns player levels into a pointless treadmill.

(If you absolutely need player levels in the first part of the game and you absolutely need the player to be able to do things in any order in the second part of the game, you can set the level limit such that the player will reach it at the beginning of the second part of the game.  That's a half-assed solution that you should avoid, but it's a lot better than scaling enemy power.)

Player levels are not pointless, even with scaling. They also allow for spell unlocks and possibly equipment gating. And also psychological things, such as progression and short term goals. It's not like the only point of leveling is to increase your stats, so that increasing enemy stats would negate it completely.

Playing both kinds of games, as a player when the mobs scale along with the character's levels it feels like I'm not actually making progress.

On the other hand, if I level up too much compared to the mobs, then it begins to feel too easy and not challenging.

Do you think you could find something in between those two? Like for zone one in many JRPGs, when you first start battling monsters you get one mob per encounter, but as you level you will start to face two mobs at the same time. Sometimes the levels of the mobs will go up as well. So the player is advancing and getting stronger and the mobs are keeping the player challenged. Then the mobs hit a ceiling and start to become easier around the same time the player stops getting much if any benefit from killing them.

To keep the player in the zone they're "supposed" to be based on their level, the mobs in the next zone start much stronger. After the player starts leveling through them, then the mobs scale a little bit in mob count per encounter and mob level. Then that zone hits a cap.

So in your last dungeon, you might be able to make the place very tough so that the player has to level up before going in, but also scale the mob count per encounter and/or mob level a little with the player's level (to make sure that the equipment gained still matters), so that when the player completes all the side quests, the last dungeon isn't too easy.

1024,

Those are great points.

a light breeze,

That's a fair point about levels.  It doesn't just have to be levels though.  It could also be weapons, spells, consumable items, etc...

DavinCreed,

That's an interesting idea.  I like the idea of there being a dynamic "range" of difficulty that follows the player.  The game allows the player sit on the high end or low end depending on their strength.