Solo Design

Dominic Matte

Solos are single monsters designed to take on an entire party at once. They're used to give the players an epic battle against a powerful creature, and are often featured as boss battles. A dragon is a classic example: a huge challenge that a party needs to work together to overcome.

There are a few very important design considerations that go into building a solo monster. A typical party of four or five players has four or five times as many actions as a single monster, and a lot more options at their disposal.

In this article I'll explain what you need to consider when designing a solo monster, and as an ongoing series, I'll examine solo monsters I've designed for my games to fit certain themes or roles in gameplay.

First things first, a bit of a warning. Solos can be a lot of fun, but don't overuse them. I once ran a game that essentially had six solo boss battles in a row, and while each of them was an interesting and unique encounter, solo monsters as a group tend to have certain weaknesses that are almost impossible to avoid without frustrating your players (at least over many encounters like I did).

Solo monsters are inherently tougher than other monsters in most respects, the most obvious of which is hit points. A typical solo monster has about five times the normal hit points for a monster of its role, because it needs to be able to take five (or more) attacks per round for several rounds. 

Solos also have a +5 bonus to all saving throws, for the same reason: a single monster will suffer a lot more effects at once than any one monster in a larger group. And when there's only one monster on the field, a stun or daze effect is particularly strong and devastating, so for encounter balance reasons, a solo monster needs to be able to clear those conditions more easily than typical monsters, or have other special ways to deal with them. A solo monster is supposed to be a challenge, and it's not exactly a tough encounter if the dragon spends the whole fight asleep.

Originally in 4th edition, solo monsters had a +2 bonus to three of their four defenses. The bonus was meant to make the monsters scarier by making them harder to hit. Well, it turned out that this didn't quite work out as planned -- what ended up happening was that more player attacks were wasted, people got frustrated, and combat ended up taking a long time. Under the current design philosophy, solos have the same defenses as normal monsters, which means players tend to have more fun because their attacks actually connect.

Another change in solo design philosophy over the years has made solos get more dangerous when they get bloodied. This is partially in recognition of nova rounds, where players dish out massive damage early in combat by using an action point to make two big attacks, typically dailies, on the same turn; and partially to keep the encounter exciting. Under the old philosophy, encounters with solos tended to drag out and get boring, with everyone involved repeating the same attacks round after round. Making solos get more dangerous over time can have several effects, ranging from simply making things feel more intense to adding entirely new tactical elements halfway through a fight. Some possibilities include a rage effect that adds more attacks or increases damage; a new aura; some passive bonuses that apply while the creature is bloodied; or even a change of form that completely alters the monster's capabilities.

In terms of attacks, solos need to be able to compete with the much higher action budget of the player characters. This is usually accomplished by giving the monster ways to make multiple attacks per round, but there are a lot of sub-categories here.

One way is to simply give the monster lots of attacks. Some monsters have a trait or non-basic power that allows them to make two (sometimes more) basic attacks per round. Hydras are a perfect example of this approach: they get one attack per head, and they grow more heads (and therefore more attacks) as combat goes on. As a special ability, hydras also have special rules for being dazed or stunned: each application of the condition simply removes one attack that round, since the hydra has multiple heads and therefore multiple brains.

Another option is to give the monster multi-target attacks, usually area attacks -- a monster doesn't need to make five attacks per round if it can hit everyone with a single blast. But make sure your monster has other options at its disposal, since smart players will spread out so that the monster can only hit one or two of them with each burst.

A third option is a damaging aura. For example, a fire elemental's extremely hot body damages anyone within a certain range, regardless of what they're doing. Auras can be a little tricky because they tend to penalize melee attackers to a far greater extent than ranged attackers. The barbarian has to be up close to deal damage and will suffer from the aura almost every turn, but the archer ranger may never even get close enough to take damage.

Instead of adding attacks, another approach is to reduce the number of actions the players can make, or to waste player actions. Simple examples include dazing or stunning, while domination can make players work for the monster. This can be another tricky one, since overdoing it makes the players feel like they have no control over the outcome of the combat. You want this kind of power to be relatively weak; to be a recharge power so it can't be used too frequently; or to have an effect that gives the player a choice. Apply an effect that deals damage if the player attacks. Try setting up walls or moving the player so they have to use their move to get back into range instead of moving to the optimal position.

The final option -- the one which I consider to be the most interesting -- is to give the monster the ability to attack out of turn. Typically this means triggered attacks that the monster can make when the players take a certain action (such as attacking or moving to a certain location). It can also mean giving the monster the ability to spawn minions to help it out, or even letting the monster attack on multiple initiative counts (for example, the five-headed dragon goddess Tiamat acts on five separate initiative counts, one for each head). Another option to consider is to constantly change the monster's place in the initiative, so that the players aren't sure when it will strike and will have a harder time coordinating.

Solos do have a few weaknesses to consider, though. The main reason that solos are fun to fight is also their primary weakness: there's only one of them. With so much invested in a single creature, solos are particularly vulnerable to nova rounds. I don't know of any monster that won't have a hard time with five characters each blowing two dailies on the first turn. There are two ways to mitigate the nova issue. One is to include more monsters in the fight, even if they're just minions. The second is not to throw a solo at the party until after they've already used some of their resources for the day.

The second major weakness is getting surrounded and locked down, especially by good defenders. Actually, one defender in particular: the fighter. The fighter is often considered the best defender in 4e because it's the only one that can completely prevent a monster from moving. When designing a solo monster, particularly a ranged attacker, keep defenders in mind. You want your solo to be able to break away from the defender somehow. You could use a harder-to-block movement mode like shifting, flying, or teleportation, or an ability that prevents the defender from getting close or making attacks. But be careful not to overdo it -- the defender will feel useless if she's prevented from doing her job for the entire fight.

Looking back on this article I realize that there's a lot of "try this, but be careful not to overdo it". Basically what this boils down to is when you're choosing or designing a solo monster for your party to fight, you want to be sure you've considered everything, since solos can be so vulnerable. It's okay to overdo one aspect if you give it a weakness in another, to cover a monster's weakness with environmental effects or other monsters, or simply to leave it for the players to figure out -- they'll feel great if they discover a major weakness part of the way through the combat.

All of this might be a little hard to swallow without examples, but don't worry, they're coming!

How do you feel about solo monsters as a design element? Have you ever created or fought against a particularly memorable solo monster? Let me know in the comments!