Game Development (Environment) theory and discussion:
I am presently making a game, RTS like the name suggests that allows the player to primarily use traps that he builds to trap the enemy (you can also attack the enemy with your NPC's you create but they are limited in this to encourage the traps capabilities) I planned to do this (since they are traps being used) within a base so that the traps can be used at a few select chokepoints to slow and even push back the progress of the enemy.

Upon looking for other RTS's to see common layout for a similar type game I found no games of today (that have the Age of Empires type building units and buildings type of gameplay) within a closed off base environment. All RTS's of today are in the open world so that more menueverability can be achieved by the player and the developer and also the variety of gameplay cannot be limited.

Is putting a RTS in a environment such as a large base such a bad idea?
Should I transition to have the base in one area where it can be entered in by the environment where the origional enemy comes from (from perhaps his base on the other side of a valley or such)?

This way the player and enemy can express themselves more in tactics rather than they would in closed environment. In short what do you think? Where should I place my game levels and what are the downside/upsides to either way of going about it?

I don't understood you question right i think, but maybe this info could help you.

There is a game called evil genius (Sierra), it's around 2 years old i think, and it plays in a base and you are the evil master and place different traps (like dungeon keeper) and combine them. Maybe you can purchase it and watch like they do it.

Ignore all other forumns related to this, I didn't like the way I said anything so I'm reworking this, sorry for the inconvience:

Why is that practically all RTS's known to man are outdoor related, yet FPS's and RPG's have no problem locking you in a dungeon with the biggest nuke known to man strapped to the back of your chest?

Based off of environment: I would like it if you would list your theories you've discovered in your games (predating or otherwise), and/or the theories you've found in games you've played. Second, based on a theory (or lack of) list the do's and don'ts of a game(s) you know to be true; or something you decided was done in the game that was really dumn.
I.E. How creative was Zelda's Ocarina of Time when you visited the mountains to help out the native people and at the end of the "level" their boss was inside a giant donut shaped corridor where you successfully rolled around in a circle (not even a big circle) until you bashed the boss in this tiny environment and killed him.

I'll offer the first theory to start it off, environments in RTS's (such as that made in Age of Empires) are loved by users and developers alike to not be limited by a closed in environment like you see in FPS's...
NOTE: don't get me wrong FPS's go all over the place in most cases now-a-days
...people love when they are thinking on the counter strategy (in RTS's) to be able to use those without conflict with the environment, plus less face it we would rather say "wow what amazing looking scenery in that lake and grass" rather than, "wow look at that shiny metal and fuzzy carpet", also when we are in the mentality of FPS's and RPG's are main goal is to kill the enemy by all means possible so since we are in the "KILL" mentality as long as that explosion looks really cool on that last combo we finished we are generally satisfied rather well.
In short my theory is the genre and concept of the game sets the feel and expectancies of the game inside, so anything that would interfere with what we expect will conflict with the player and result in a bad game.

I don't really understand your point either, both starcraft (when I'm not mistaken) and for example Emperor: Battle for Dune have certain levels inside spaceships, in a closed environment. It works great in those games, but are clearly meant as, although important missions, mini-games or gimmicks. People just don't like the limits these closed environments give (both limiting the developer but especially the player). Personally I loved those special missions of Emperor: Battle for Dune, and I think the Dungeon Keeper series are still part of the better strategy games out there. Having said that it's good possible when designed properly. On the other hand it's kinda the hype at the moment to make large outdoor areas (like Ground Control I or II), and honestly I like those environments too.
Don't forget RTS is all about large battles conquering the enemies territory, and in that case outdoor bigscale terrains are the place to be, if you want to make those battles seem epic. Btw, when I think about a game like Battle for Middle-earth I and Warhammer 40k: Dawn of War, then I think the scale of those terrains actually aren't really amazingly large, but do give the kinda epic feeling anyways.

Cheers