LET'S IMPROV! A COMEDY FORUM GAME

The key to comedy is an average guy or gal, dealing with insurmountable odds, without the tools necessary​ to deal with the problem, and yet never giving up hope!
Consider this: The scenario is a room full of people with guns. For an action movie we would put Chuck Norris in there. For a comedy, use Woody Allen.
You're already laughing! How would they deal with the problem? Chuck Norris would enter the room and already have half of them decapitated, then kick a gun into the throat of another--before we can count a beat, they're all down.
Woody Allen on the other hand, well, he's a neurotic, cowardly, nervous mess. But he's got wit. "Oh, oh my, d-don't shoot! I'm a bleeder! Look, it'll ruin this good rug..."

The character you're righting or acting, has the right to win. Considering their own world views, philosophies or experiences, they have the right to win. They would attempt to solve the problem, clinging to hope, using their own skill set (which is lacking in what they NEED) to solve the problem.

In Big, Tom Hanks has to try and reverse the curse of suddenly turning from a 13 year old boy, to a 30 year old. Without being witty, he tries to solve this problem by first returning to the carnival and finding the gypsy machine. Then trying to convince his mom that he's her son. Her reality is that an out of breath 30 year old man, in sweat pants no less, has barged into her house. She reacts in a way that allows her to win (assuming he's a crazy rapist or some-such, attempts to defend herself, to get him to leave, to call the police). And it becomes this funny scene, because both characters act honestly. They reveal themselves as who they are. And who they are, is not perfect.

Even if the hero is a Hero, to be funny, s/he needs to be ill-equipped for the situation. In One Piece there are laughs aplenty, because the characters stick to their own moral compasses, act in ways to make their own agenda succeed; and are usually without a solution to a problem. Ussop lies at every turn to make himself look better, Zorro has no sense of direction in life or in reality, and Luffy's only solution to any problem is to punch it. These characters, and the rest, all have crippling flaws for action heroes but they never give up and cling to hope. Hope is the heart of comedy.

The essence of being funny isn't saying something silly or witty. It's being completely honest about who you are, discarding social inhibitions.
Therefore, let your character act like how your character would act. Don't be afraid to look like an idiot, or mess up, or seem odd. Because in reality that's what humans are. We drop things, trip, forget names at just the wrong moment, fail to notice something, or even fart.

Another thing to remember is that knowledge is a skill. A character without the knowledge that there's a murderer behind them, and believing that they are totally alone is potential for drama or terror. But if the character farts lengthily, or something totally off-putting socially; maybe the murderer has second thoughts? We, the audience, laugh because we can see two characters being truthful to themselves and the situation. Regardless, the murderer wouldn't give up. He wants to murder. The other person would continue to try to relax. The murderer waves away the stench and leans forward for the kill, but then the other person kicks back his recliner, unknowingly smacking the murderer in the groin with the chair.
This can go on and on as long as neither give up hope or the situation is made clear. As soon as the relaxer notices the killer, the comedy is over.