Raising the stakes in creative writing ratchets the tension and the pace of the story. It increases the danger, the risks. Readers become more invested because of what is at stake. If a writer simply puts two characters in a room, the results can seem arbitrary. They can have a discussion about toast, teach each other to juggle, dance around in their underwear... the possibilities are endless. Raising the stakes limits the choices and forces the characters to act in revealing ways. Setting the room on fire or having a madman break in with an axe, presents a threat and an obstacle for the characters to overcome, creating drama. Will they live or die? Will they fight? Will they panic and create more problems?
Some writers choose to find the story along the way, but they risk veering off pointlessly. Outlining the plot of a dramatic story gives the writer a set course. Of course, the writer can alter her path if things aren't working, but having that spine, lets the writer know the direction and purpose for the scene in the overall story, so she can focus on language and sentences best suited for each particular point in the story. If she knows a character is going to die in the next chapter, she may create empathy and compassion for the character, so the death will have greater dramatic effect. She'll also be able to see where the story lacks action and drama before bringing the outline to life on the page.
Increase the drama of any story by giving the characters primal needs, particularly the protagonist. Primal needs are the core motivations for all human beings, and they help readers relate to and invest in characters. A protagonist might be taking on terrorists or supernatural monsters, but what's the reason he's really doing this? He could be trying to save his daughter, win the love of a woman, or gain the respect and love of his fathers. Primal needs make characters human. They create drama, because they're deeply important to the characters.
Strengthening the bonds of character relationships creates more drama and tension. While two strangers battling against each other can be compelling, a father and son or two brothers engaged in the same battle can add layers and depth to the conflict. Family relationships evolve over years, building up painful memories, which can inform the conflict in a multitude of ways. As an exercise, make two characters related by blood or upbringing. Create backstories to sift out past indiscretions and resentment. Try rewriting the scene with this new dynamic and see what new drama unfolds.