What mechanics can be added to a fantasy game?

Make a big deck full of good things (helpful supplies, special equipment, maps, weapons, lucky talismans, etc.) and bad things (monsters, traps, evil curses, 'equipment breakage' cards, 'weapon jam' cards, etc.). As the players explore, everyone else gets to throw things in their way.

So, as one player makes it to the room with the treasure, you can drop the 'scarab beetles' on them. Fortunately, they have a few oil lamps to throw at them (discarding), but it will make it difficult to explore the next room.

Next, it is your turn to explore a room, where another player plays mummy rot disease. Having no defense, you lose a few of your crew, but aren't dead yet.

Then, the next player goes down a corridor. Someone decides to let loose an indiana jones style boulder at them, and they have to run. Since they were close to their goal, you "help them out" by playing 'trap door' - They escape the boulder, but they are now in a different area of the pyramid.

Sound good?
Sounds like dungeoneer ^_^ an sounds like a generic fantasy-adventure board game (me mean no harm), in any case, each round one player will play as the mummy king, and will throw bad things on the players, that's part of the concept of Competitive backstabbing as you defined pretty well!

Such as a trap door that requires two people to be present to disarm the trap.

or make some treasures too heavy to move by one player... thus players have to strike a deal to haul it toghether and split it...

make rooms dark so that you must have a torch card to see it's contents, but put a very limited number of torch cards so that not everyone will necessarily get them... which means you have to have another player hold a torch for you... or else buy/trade something for their torch.

It depends on how you do things, but there are lots of things you can do. It will depend on whether everyone is automatically equal or if you give each player a certain advantage in an area, such as a skill or class. If you build class structures in, it can automatically generate interdependance/cooperations, but usually at the cost of complexity. (my $.02 anyway)
Checked...after all that's the concept Competitive backstabbing, and the game force it on the players (:.

By me saying that the game feels too much like simulation' I mean that it's act like talisman or dungeoneer, it's a simulation of a dungeon crawl.
but what cleaver mechanic can I add?
In dungeoneer for example there's the peril points, when a player enters a room he get's peril points and good pooints, then the other players in their dungeon master phase can drop bad things equels to that players peril points. In my game each round one player get's to play as the mummy king and do some bad stuff. but apart from that what other mechanics can I add?
OR as I said... in general what mechanics can be added to a fantasy-adventure game to make it {EDIT=>}NOT feels generic one.