So, the last session I tried to make an encounter where my players had to escape from a burning house. Unfortunately, it turned out to be a boring bunch of pass-or-suck checks. How can I make this interesting?
You might want to take a look at the chase rules in the Gamemastery Guide; my DM used them for us once when I was pursuing a fleeing enemy, and I don't see why they couldn't be adapted to a burning building scenario. The basic gist of the rules is that you have a series of obstacles, each of which can be overcome by one of two checks, and the players get to pick how they want to overcome the obstacle. There wouldn't be an enemy to gain on, but you could have the fire metaphorically chasing them from behind, in which case if it catches them they start suffocating from smoke or some such dire consequence.
Make it interested by adding challenges which are interesting in their own right. The fire can play a number of roles. It can be as simple as background scenery, a cause for the challenge, or simply add a time dimension to something that would otherwise be be straight forward. Some examples might be illustrative.
Combat in Fire
Perhaps the fire was started by an enemy that wants to eliminate the players. But the enemy needs to make absolutely certain the PCs are killed, so he sends in henchmen to either verify the kill or help ensure it happens.
Of course, this presupposes that the henchmen are either immune to fire or so fanatical they will expect to die. (Mindless undead perhaps?)
The fire could serve as just scenery. But perhaps you place "active fires" on the map, and moving through those or worse being forced to stay on one could cause fire damage. At your discretion, you could also add smokey areas which provide concealment. You could consider dealing with suffocation from smoke damage, but that is probably more trouble than it is worth.
Locate someone that needs to be rescued
The building might be large and mazelike. The heroes now need to explore it to find the person they need to rescue. You can have the fire play an active roll, forcing them to pass through areas, perhaps collapsing upper levels. But alternatively, you could just use it to set a timer. The rescuee will die in X rounds, they must find the rescuee and get out in that time. Now they have to face decisions. How do they search? Do they split the party to cover more ground? What if there are hostiles in there, or just the possibility of hostiles will affect the decision to split up or not.
A series of challenges.
Perhaps all they have to do is escape. But they need to find the way out, and deal with obstacles appropriate. In a building it might be areas blocked off, doors that are locked, etc.
This risks becoming the "succeed on roll or suffer" that you want to avoid. But you can mitigate that by providing choices. When they come to a locked door, do they use magic to destroy it, use force to destroy it, or pick the lock? If they come to an area on fire, do they rush through just accepting damage, try to go around, or perhaps try to do something (coat themselves in water? Breathe through clothing?) to mitigate the damage before rushing through?
And of course, some of these examples can be combined or shift from one to another.
Of course, its worth pointing out that a lot of this is depending on their abilities. Fire becomes a lot less intimidating if you have serious protection from fire or can regenerate fast. Escaping is easy if teleporting is an option or flying is an option and you can find an upper story window (or break through a wall to make one).
Not a definitive answer, but here are some suggestions for getting creative with fire:
In other words, in addition to your classic dungeon manipulations (e.g., labyrinthine halls/rooms, clever combats, rescue/escort a noncombatant), there are a few nice tricks to use that rely on the fire itself.
In addition to, or instead of, the chase idea, you could create a countdown situation with a timer that is counting down that they can visually see. A creative timer based on a candy bowl has been suggested here:
The advantage of the visual timer is that it adds something more than dice rolling, both visually and tactile.
For my most recent D&D 3.5 game, I actually stole the idea of "skill challenges" from D&D 4e (which I generally dislike), modified it very heavily, and plugged it in to 3.5. In my incarnation of the idea, it's essentially a challenge abstraction. My players loved it.
Here's the general idea:
Two notes of caution: a skill challenge, being an abstraction of events, shouldn't take up much more time than a reasonable-length battle. Also, there should be a reasonable chance of (and consequence to) failure.
This is a great way to encourage participation, make them feel like they have agency over what occurs, and frankly take some prep work off your hands as far as story goes, since they build that section of story as a party. My players have had a great time with it, and the story has become much richer for it.
(Finally, I have to credit Rodrigo Lopez of the Critical Hit podcast for the ideas of rolling initiative and using any skill.)