[Theory] Hidden passageways

The obvious problem with that is that these spots will be reachable by soldiers and demomen as well, and getting attacked by even a slightly skilled player from behind is never fun.

These would have to be VERY well balanced to even be remotely do-able.

That's not something that would benefit TF2 maps. First of all, if a map is going to have an extra path, it needs to be useful. If the path isn't useful, then it'll only serve to fragment teams by sending them down a bad path.

But if you've got a useful path, then you shouldn't hide it from players. It's more fun when you know all the options you've got from your current position. TF2 players like to discover new strategies within a layout; having to waste time discovering the layout itself first just gets in the way.

I also think you shouldn't do it. while discovering new ways to play a map can be fun, it makes the map less fun for newer players, because not only do they not have the option of having that passageway, but they also will get easily flanked by people using the passageway and will die way more often than they would normally

Yeah, I'm with the "no thanks" crowd. TF2's style doesn't really mesh with "secret routes". The closest thing would be certain arrangements of platforms and ledges that are of particular use to scouts or spies.

The former, because they have double-jump and FAN-jumping. The latter, because they may prefer to run along some slim ledge or pile of junk to avoid a crowded hallway/ramp/corner.

ya that doesn't really fit into tf2 style too much,

and also once you get some regulars on your map they will always find ways of navigating your map that you never even intended or thought about.

In multiplayer, you can only make any "secret" passageway secret for so long, and then everyone starts using it. Then it's just another alternate route. Not worth the effort just to give an easy victory to the first person lucky enough to find it.

An analog to the "secret passage" idea in Valve maps is one way gates.

The problem with genuine "secret passages" is that players always want to be headed towards the fighting. If there's a safe route that's three times as long as a more dangerous route.. they'll choose the dangerous route every time. Requiring elaborate jumps tends to cause players to avoid the route as well.

Thus, the one way gate. They allow the safety of a secret passage while at the same time keeping players moving towards action. Dustbowl is an easy example, it creates an obvious location for a forward base. It's tough for the defense to clear it out, but if the offense gets careless with opening the gate it's certainly possible.

Alternate 'secret' routes, like vents and stuff only really work well on A/D maps in favour of the attackers. They have a better flanking point, but move slower because of crouching.

If it's an effective passageway, put some lights next to it/shining onto it. People tend to move towards lighter areas in games, it's what we just do.

Then again, paths that are unusual and not marked obviously enough will sometimes be used so rarely it kind of counts as a "secret" passage, e.g. jumping from the Badlands mid over the spires directly on the balcony of the buildings.

Just keep in mind that Soldiers and Demomen can get almost anywhere - don't just make paths for Scouts, those can't exist.

By this do you mean like the passageways in doom?
Obviously of-course you do. It would bee cool however would not go with the tf2 style and there's no way of choosing what classes can get through this door.