It's the mentality of size=time and stuff to be searched=difficulty. Technically a small, heavily filled room would take longer to search than a larger room with little in it.
I guess I was unclear. I did make my posts far too late in the night.
I'm not saying size=time. Actually that's what square counting does. Instead, I make a judgement call based on all the environmental factors what the DC should be. It is no different than nearly in assignment of DC in 5e. 5e leaves much of this to DM discretion. There are not detailed mechanics to determine what the DC should be for scaling a cliff. The DM has a general guideline and assignes a rating based on the steepness, whether there are plenty of spots to grab hold off, is it wet and slick, are there lots of hornet nests or bee hives, how windy it is, and other factors.
In terms of preparation, I like DC because I don't have to determine the search DC for every room. I only need to come up with the DC as needed, and can easily do so on the fly during play. I find it harder to do so if I have to count / estimate squares.
Even with my method, I don't require time to search an empty room, since a passive search would instantly show there isn't anything (unless they search for secret doors or traps).
Fair enough. I do the same.
As for counting squares/hexes for rooms, you can quickly do this when designing the dungeon (or estimate if you wish), and simply add it into the room notes.
But with DC assignments, I can do on the fly, during play, and only when I need it. I already spend enough time on game prep. I prefer to spend it on story, NPCs and fun stuff. On the other hand, I realize i'm make a bigger deal out of this than it warrants. We do often include room dimensions in the descriptions and often have to count squares to answer player questions about a space. But anything to make my life easier as a DM is appreciated, and the DC approach seems to make my life easier than counting squares. Your mileage obviously varies. That's fine. I think both work under the RAW.
Part of the advantage to having the time being based on the size is it gives consistency to the players. Some adventures are time based, and having an idea on how long it will take to search a room helps determine actions. If they roll badly, it can eat up time they don't really want, because their characters would have given up before the time required. If you still like time based DCs, simply let the players know the average time (middle DC), and have them decide how long they are willing to search before the roll. That way they can still make the attempt, but set a minimum DC they can achieve.
That's true. Especially if the players can see the map. If they have a map and are planing a prison break or something, I might use the square-counting mechanics for that session so that they can calculate time needed, etc. On the other hand, I could just give them DC numbers for each room based on what they know about it. I agree that giving the players an average time is a good idea.
