Dungeon Master: Ambushes

There are many tactical situations players can find themselves in. An iconic classic is the ambush. It mixes things up and provides the opportunity to safely remove a threat, to have a chance to win in a situation where otherwise there'd be no hope, or to put real fear into your players. However, it's a careful balancing act that is easy to mess up. A challenging ambush against your players could end up as an embarrassing defeat for the players. Having been on every end of an ambush I can think of, I hope my insights will provide some use to someone out there.

A Player Ambush

A Weak Enemy

An ambush against a weak enemy, either due to numbers or the monsters themselves, only makes things even easier. This typically results in an even less climactic game and in many cases makes players wonder why they even bothered. The more cinematic your campaign is, the more that this is probably true. However, there are exceptions. The most common one is if your players like dungeon delving. A weak and easy encounter can still provide tension in this case because your players are expecting a long war of attrition. The tension then doesn't come from the encounter itself but from the possibility of being starved of valuable resources that they'll need later. I've also seen it used for great effect for the story. Wait, this is the big bad's elite force? Something seems wrong. And then the trap is sprung or the complication is found. It can also be used to say something about the enemy and for the players to say something about themselves.

A Well Matched Enemy

Players look for opportunities for their characters to succeed. They typically want to do what they can to avoid the death of their character. Naturally, ambushes against a well matched enemy are one way to increase odds of survival. There is still room for things to go sideways, but if the players earned their advantage there is nothing wrong with giving it to them. Like the previous example, there is the attrition angle to add tension. However, things could also change from being a situation where the entire party is at risk of death to where one or two players might die. However, for a player that doesn't want to be one of the “lucky” ones, that could be more than enough to make things tense.

Overwhelming Odds

One of the coolest situation an ambush can bring is the part where overwhelming odds become conquerable. However, it is difficult to get right. The encounter can be tough but not hard enough to really give the massive feeling of accomplishment at the end. It can also be truly overwhelming but remain so even with an ambush in place. This may not necessarily be a problem, if the objective is specific and not to simply kill the entire enemy force. However, this still provides a similar problem. How do you make the objective super difficult to complete normally, but possible with an ambush? There is also a criticism that I think is quite fair. Isn't this a bit railroad-y? I mean, I may be assuming the correct way to approach the encounter.

If the only way to get past the encounter is an ambush, I would agree. However, if an ambush is one of many possible routes, each with their own dangers, things look far better. Of course, some ideas may need to be hinted and seeded to give your players somewhere to start. And if they arrive somewhere other than you envisioned from those seeds, even better. No railroad there.

A classic situation is a large group of enemies. These enemies can be dropped in a single not lucky hit. However, their sheer number makes them difficult to fight. In the case of an ambush and a surprise round (assuming 5^th edition D&D rules), you can reasonably estimate how much will be left afterwards. This essentially means that the encounter we are designing is the one after the surprise round, but the free hits can make thing seem more impressive when not overused. This might not be enough to make things even. Only by using the environment or some other factor do things finally fall in line. The issue is that unlucky rolls leaving more enemies than expected after the surprise round will mean the encounter remains impossible. 

A Monster Ambush

Weak Monsters Strike

Surprise is a powerful tool. A weak enemy could be made formidably or at least worrying for a party through this technique. Imagine a party of level ones going through a forest. One wolf isn't much of a threat. However, if it has the chance to dart out of the trees and strike a target of its choice before being noticed, it becomes a threat. Not to the party, but to an unlucky PC who doesn't want to die. This can be further expanded by using non-standard tactics.

The most classic encounter to mix things up is the stealth attack encounter. Some creature coming out of the unseen shadows and attacking a player before retreating back to where it can plot its next move. With this advantage of stealth to return to, it can continue being difficult to fight. However, some creativity (readying an action for when it flies into the light of the torches or to light torches and throw them into the darkness to leave no room to hide) makes things no longer a challenge.

Formidable Enemies Strike

Giving a surprise round to a group of well-matched enemies has the potential to go very badly for the PCs. Some might die or be dropped before even having time to react. We DMs just live with this fact for our NPCs, but players often don't like it. After that, they then need to find some way to pull a win or at the very least avoid a loss. It isn't a good situation to be in.

Having said that, it is manageable. The party just needs some way to bring things back in line. It could be the use of an item, it could be clever terrain use, it could even be the assassination of the leader. It could also be the not very honorable but practical retreat. However, throwing them into a situation like this without a way to get out can rub players the wrong way. The exception is if players did something dumb. If it's their fault and a stupid decision in the beginning, or they knew what they were possibly getting into, it tends to go over better. However, it probably shouldn't be an instant total party kill if we want things to be fun. There should be a risky escape possibility or at the very least grant them one if they think of something clever.

Ambushed by Overwhelming Odds

I can't remember the last time I've seen this situation. Maybe this could work if your players did something stupid and they are in a campaign where death doesn't mean as much (revenant campaigns rock). It might also work in very specific cases. If killing the necromancer makes all their skeletons crumble, it could work. However, this situation's difficulty is already changed due to this condition so I'd argue it isn't overwhelming odds. However, generally I'd say avoid this kind of thing. If you are even thinking of this one, you should have a good reason and be cautious. The already overwhelming odds just become more so  when they also have the element of surprise.