What are good DM strategies for adjusting an Encounters session to handle various parties?

Question

Our local store has been running the Encounters sessions, and one issue that the DMs have encountered is that the difficulty of the fight can vary drastically based on not only the number of players, but what characters they bring. We've had cases where ten players have arrived with not a single leader between them. Since there's five players per table, we're supposed to run the fight as-is, but we've ended up with TPKs. On the other hand, some times the table just has the right combination of tricks and blows through the fight with near-zero difficulty. Worse, it's often not obvious until mid-encounter which way this is going to go.

What are good strategies to try and level out the difficulty?

Answer 1

Here are some ideas for helping the party:

Reinforcements. Hold a few enemies back. They can run in if the party has an easy time with the fight. Or they can hang back and you can "accidentally forget" them. Or they run in when the fight's all but won and the players can focus on the reinforcements instead of dividing their attention to deal with them.

Reconnaissance. Give the players extra info about the fight. Ask them for perception checks that the module doesn't request, so that they can see the other side before they themselves are spotted. Give them a chance to play their attack and maybe even get a surprise round. I wouldn't use this right off the bat, but if the party struggles through one combat, try this the next time around.

For hindering them, my best suggestion is to focus fire. My party likes a challenge and they're playing reasonably powerful characters. The best way for me to make them feel threatened is to pick a PC and try to drop him. Usually I end up going after one of the strikers. They make themselves available and they're hittable. I only go after the defender when he needs to feel good about his high defenses. Seriously, I can't drop him. If the leader and wizard are left open I'll target either of them, but they usually hide in the back and it's not worth the actions to get to them.

Answer 2

Look at the party composition before you start the encounter. As a GM you should fairly quickly start getting a handle on what synergies work (and hopefully who your tactical and creative genius players are) just look.

The first thing I would look at is class balance. 4E is strongly influenced by MMOs: you need tanks, healers, strikers and controllers. If you are missing strikers or controllers you're probably not too bad off. If you don't have tanks or healers you're probably going to have to make things easier as you have nothing but a bunch of glass cannons.

Also you can bring in environmental details to help the PCs--have them start making perception checks to notice advantageous situations--sun in the eyes, hidden gopher holes, what have you.

Reinforcements can go to either help your party or hinder them--or both. A wild bore might just decide the closest target (the NPCs) is the biggest threat and then go after the PCs (effectively moving some of the difficulty from the middle of the fight and tacking it onto the end).

Tactics are another one--if you aren't playing super smart NPCs--they can easily choose non-optimal targets, start to break and run away or any number of other personality defects causing them to be stupid. (Leaders stopping to speachify is a classic.)

And, if I understand what you mean by encounters (one off combats) sometimes winning is ok--the PCs then know they can loose.