Among the many iterations of Dungeons and Dragons, none inspire and promote insanity quite like 3.5. I’ve witnessed many things in my time as a DM like a character killing a Great Wyrm in one turn(his name is banned among certain friends), a flying castle being used as a weapon, the legendary “Ranged-Touch Grapple” which was created during an all-night session, and similar hauntingly crazy things. It seemed like the more we learned about the system, the more we felt free to do the things that we wanted to do. Despite having all of these rules, the system allowed for quite a bit of freedom, and even more potential to absolutely break the game. Yes, Pathfinder was technically an improvement, but by improving the game it removed some of that potential for craziness. Balance isn't always a good thing, and 3.5 displayed this brilliantly.
The concept of templates still existed with 3.5, something that 5e has seemed to abandoned. A template is basically a way you could modify a creature, like Undead, and it explained what stat changes and and abilities it would gain. This allowed you to create such things as the previously written about Bearrasque with little to no hassle. Yes, you can still do this in 5e, but for the most part you'll need to create them to. This opened up many doors for customizing encounters and making things more interesting.
If you simply look at the classes, you'll probably be immediately overwhelmed by the sheer number of options. All the base classes are there, but true customization comes in the form of Prestige classes. The combinations were endless, especially when you added multiclassing. Things like using a castle as a weapon were actually on the tamer side of what you could do. With the release of the Book of Nine Swords, you actually had a class that could be a combination of other classes without actually multiclassing. Do you want sneak attack damage? They can get it. Do you want to cast spells? They can do it. Increase your AP every time an enemy misses? There’s a stance for that. The options were endless, especially when you took the Master of the Nine prestige class.
I know I wrote an article all about how Pathfinder is a better system, and I will forever believe that, but that doesn’t mean I don’t love 3.5 and the customization it offers. Take a look at the homebrew section of the wiki, and you’ll see hundreds, if not thousands, of classes made by people who love the system. I look at 3.5 as my first love, with all the fond memories and joy we shared, but I have long accepted that those are just memories. I have moved on to better systems, ones where I don't have to look up the rules to grappling every time my halfling feels the soul-shaking desire to grapple something. You will forever have my heart, 3.5, maybe we'll find each other again the future when we've both grown and matured.
Justice of D20 Collective.