At first I was a bit hesitant about creating encounters on the fly for 4E. I slipped into this mindset about planning everything out. While I still feel combats in 4E worked much better as set pieces, at times PCs might go off into another completely different direction. When they did that, I felt combat likely shouldn’t be an option as I just wasn’t comfortable enough creating something up on a whim. I wasn’t sure if it would be challenging enough (or too difficult).
What I failed to notice was that the monster math in 4E was very open to DM. It just took some effort to sit down and work it out per level. It was deceptively hindering at first but when you really looked at it, you saw how simple and elegant it was.
Then there was the Sly Flourish DM sheet, where the guy did what we all should have done at the beginning, just create a spreadsheet that does the math and print it out. Granted this was using adjusted HP and damage with the ‘updated’ monster stats, but it laid out how simple creating monsters were.
The DMG did have a similar table but required a little calculation. Still if the effort was made, you could instantly create a challenge appropriate fight for PCs. All that was needed were a few keywords for damage types and you had the core of an interesting monster.
I really think one of the biggest flaws in presenting 4E was not including a fully sketched out table like this. Also not really providing more monster themes was another failed opportunity. Maybe they wanted to hide how easy this all was. That in a flash, you could make up custom monsters with damage, HP, attack bonuses, and defenses that would be level appropriate.
Honestly, I’ve found the openness of the entire nuts and bolts of the game refreshing. You could pull things apart, cram things together, and 9 times out of 10 it would work fine. The elegance in being able to quickly create encounters just worked so well. It’s something few folks are willing to admit, that 4E gave the DM a lot of tools and freedom to make really cool stuff. I don’t think I ever really bothered making up custom monsters with older editions like I did with 4E. Best of all was that it worked very well.
Sadly I don’t think this was ever really explored more, and I wish more emphasis was placed on the DM taking stuff like this and running with it. While it was great having pre-made monsters and traps the idea you could whip up your own in a snap should have been promoted more. It’s one of the elements of 4E that made it my favorite edition.