Bosses

Here's how you put bosses into your dungeon.

You Don't Need Bosses

The first rule about bosses is that you don't need bosses.  A dungeon can be an excellent experience without one.

Bosses are fun.  They can be the charismatic face of a dungeon, or they can be the thing that needs to be beaten in order for the good guys to win.  (If that's the kind of game you're running.)

But bosses can also be fragile.  They can be too easy (if they fail a roll) or they can be too hard (if the party fights them in a depleted state).  As far as emotionally-charged centerpieces go, bosses are pretty fragile.

If you must have an emotionally-charged centerpiece of a dungeon, may I also recommend: stealing a certain treasure, rescuing a certain person, or breaking something.

How to Keep Players From Fighting Bosses When They're Depleted

Show them the boss fight is coming, and give them a chance to prepare.  Don't spring it on them.

How to Keep Players From Steamrolling a Boss

You could use multiple enemies instead of a single foe.  The Shadow Council, instead of a dragon.  This spreads the rolls around, smooths off a lot of the statistical rough edges, and produces more reliable results.

You could make it a puzzle encounter.  Only a certain weapon can hurt the boss, it can only be defeated in a certain way, you need to avoid a certain attack, etc.

You could make it too powerful to defeat in a straight-up fight.  This is the simple method of doing what I recommended in the previous paragraph.  Bosses that are numerically impossible to beat cannot be overcome by running up to it and hitting it with your strongest attacks.  You'll have to scheme.  (That's what LaTorra does here.)

Dynamism

I've talked about dynamism before.  Essentially, you want the fight to evolve.  Every 1-2 rounds, the circumstances should change significantly enough that the players will have to re-evaluate their tactics.

If the circumstances never evolve, you're left with. . .

Turn 1: I attack.  I hit.  7 damage.
Turn 2: I attack.  I miss.
Turn 3: I attack.  I hit.  3 damage.

Dynamism in a boss battle can come from a few places.

The simplest place it comes from is just from resource depletion.  The fighter is at 1 HP, and must now change tactics and back away from melee.  The wizard is out of his best spells, and must now find a way to leverage her second-rank spells.

There's also some crude attempts at dynamism: enemies that unleash a very powerful attack when they're bloodied, or bosses that change form.

These are a step in the right direction, but oftentimes the people writing them miss the point.  A dragon that gets a free fire breath when its bloodied isn't dynamic unless the fire damage is enough to force the party to change tactics.

And anyway, HP damage isn't a very dynamic mechanic anyway.  (I'd actually argue that it's the opposite--HP exists to help players predict how much more risk they can accept.)  A player might not play very differently between 60% and 100% HP.  Only when they start getting low will they start thinking about changing their tactics.  And besides, you can only damage HP so many times before someone dies.  HP isn't ideal.

The dynamism in a boss fight should come from the same places as other fights: circumstances change in such a way that the players need to come up with new tactics.  They don't have to be fancy.

Examples:

• The dragon takes off.
• The dragon lands.
• The dragon burrows underground.
• The dragon sets the forest on fire.  (Always a favorite.)
• The dragon leaves.  It'll come back and drop a cow on the party.
• The drakencult arrives to defend their dragon.
• The drakencult flees once the dragon is bloodied.
• The giant grabs someone and prepares to throw them.
• The giant overturns his bathtub, causing players to risk being washed away.
• The giant blows hard enough to extinguish everyone's torches.
• The wizard turns into a swarm of hornets with wizard faces.

Remember that it isn't dynamic unless it forces the player to re-evaluate their tactics.  A giant that stomps the ground (Dex check or fall prone) isn't very dynamic.  There's no chance to react (except a passive Dex check) and characters that fall prone will probably just stand up and resume their generic strategy: fighters swing swords, and wizards wiz.

Wind-Up Attacks

A big gout of dragon breath isn't very dynamic if it's just a Dex check, but how about this:

At the end of the first turn, the dragon takes a deep breath.  At the end of the second turn, it uses its fire breath attack.

See the difference?  The players have a whole turn to react.  Some players will choose to stay in melee, some will jump on the dragon's back, some will take cover.  We've given them an interesting choice, just by telling them that something big is coming.

You can have the wind-up attack trigger at the end of the next round, or on the boss's action at the end of the next round.  (One gives everyone an interesting choice.  The other gives players an interesting choice only if they succeed on their Initiative checks.)

Examples of Wind-Up Attacks:

• A giant could literally wind up for a haymaker that will deal double damage next turn.
• A giant could pick up a boulder, preparing to drop it on someone's head.
• Tongues of fire could start licking up out of the ground.  Better get off the ground before the floor is lava.
• The dragon starts beating its wings.  Next turn, it'll blow people away.
• The dragon starts beating its wings.  By next turn, it'll be too dusty to see anything.
• The dragon roars and stalactites crack.  They'll land next turn, and are especially dangerous to players who spend their turn ignoring the threat.

A Changing Landscape

There's also some subtle dynamism incorporated into regular fights against groups of enemies: enemy death.

A group of orcs becomes less threatening over time, as the players kill orcs.  They might fight three orcs the first round (taking at most 3d8 damage), two orcs on the second round (at most 2d8 damage), and finally a single orc on the last round, because orcs don't surrender (at most 1d8 damage).

This gradient allows players to (a) see their progress, and (b) react to a combat that is changing.

Bosses sometimes lack these nice benefits.  Be sure to give the players a constant update on how the boss is looking, so they can see their progress.  Is the boss sneering through a few cuts, or coughing up blood as they lean on their staff?  I always tell players when enemies are bloodied, and I think I've literally drawn health bars before (which is a bit dissociative, but doesn't really give them any information they don't already have, assuming that you're being very descriptive).

I've talked about dynamism in the sense of round-to-round changes, but you can also have gradual changing that force the combat to evolve.

Examples:

• The boss gets weaker as it takes damage. (See also: wizards running out of spells, dismemberment)
• The boss gets tougher as it takes damage.
• The arena decays: gets smaller, floods, sinks, or catches on fire.
• Reinforcements arrive each turn.
• The party must fight the serpicant in a different room each round. 

A party that is kiting a serpicant throughout the dungeon might know that eventually they're going to get cornered and poisoned--unless they go through an unexplored passage that might give them they time they need to kill it.  See, interesting choices.

You can also have some dynamism come from unique arenas: maybe the arena is criss-crossed with enough acid streams that the party will have to change up their generic tactics a little bit.  (This is what people mean when they say "interesting boss fights need interesting environments".)

Dismemberment Rules

You can dismember monsters with crits or with combat maneuver rolls.  Generally, allow players to target whatever the hell they want.  It's a great way to evolve the combat and give a sense of progress, outside of regular HP depletion.

Want to shoot a manticore's armpit so it can't flap it's wing?  Sure.  Now it can't fly.

Want to shoot a dragon's armpit so it can't fly?  It'll make a rough landing, pull out the arrow, and take off again.  (Dragon's are tougher.)

Want to lop off a displacer beast's paw so it loses a claw attack?  Fine by me.

I don't have any hard rules for dismemberment.  It works for me.

Unlucky Saves

Players love telling stories about how they killed the boss in the first round, when the boss failed a save vs polymorph and got turned into a snail.

I honestly think that these stories are a feature, not a bug.  If a player wants to spend a round casting an unreliable spell, they are free to do so.  I like giving players that freedom.

However, that unpredictability still runs counter to many people's instincts, who think that a boss should be something that requires many rounds of combat and drops at least one character to 0 HP.

Well, for those who would to blunt the sword of RNG, I recommend Ablative Saves.

Ablative Saves

This is going to get compared to legendary resistance in 5e, so I guess I should start by talking about that.  This is legendary resistance (typical for epic boss monsters):

Legendary Resistance (3/day): if the dragon fails a saving throw, it can choose to succeed instead.

They wrote this rule to insulate dragons against unlucky saves.  And as a rule, it sucks.

It sucks because it creates a separate track to victory, then forces the players to choose between them.  Do they try to damage the dragons HP?  Or use things that cause saves, hoping to whittle down the legendary resistance enough to fire off a polymorph?  

I once wrote a class that didn't deal HP damage, and instead attacked enemies' Morale score, defeating them by destroying their will to fight.  It might be fun if the whole party was attacking Morale, but if not, you're just splitting your attention in two directions.

So dragons are effectively immune to casual polymorph attempts.

Here's mine:

Ablative Saves (at-will): if the monster fails a saving throw, it can choose to succeed instead and take 20 damage.  Alternatively, it can take 10 damage and suffer from half the effect.  All Level 9+ creatures have this ability.

Now everything is back on the same track.  Failed saves now damage the HP total.

Fiction-wise:

The dragon shudders as power word: kill rips through its body.  It slumps over, gurgling out a death rattle.  But the party's cheers die on their lips as the great wyrm somehow staggers to its feet, a few seconds later.  Black blood leaks from its furious eyes.

OR

The wizard could feel their polymorph spell twist as they cast it, warping around the psychic bulk of the dragon's soul.  The dragon didn't deflect the spell entirely, but neither did it suffer from the full brunt of its transformative energies.  Instead, some sort of snail-dragon now faced the party, with huge claws pulling its coiled rump around the cavern, green slime dripping from its once-fiery maw.

GLOG Rule: Affecting High-HD Enemies With Spells

A spell cannot affect a target if the [sum] is less than the target's HD.

I've been using this rule in my home games for a while, but I forget if I've posted it on the blog.

Action Economy

Bosses also sometimes get held up by the sheer number of actions that they need to take in a turn.  5e solves this by letting bosses take extra actions over the course of a turn, in the form of legendary actions.

This is perfectly fine.  It smooths out the damage curve, removes some variability, and gives the party more flexibility to respond when an ally is injured.

Of course, there's nothing wrong with letting the dragon take all of it's turns at once.  Spikier, traditional damage.  And besides, if the dragon is using wind-up attacks, it's effectively making two attacks each turn anyway, which has much of the same function.

Threat

Bosses who focus fire on a single character should have no problem killing them in one or two rounds.  On the other hand, bosses that focus fire usually ignore the rest of the party.

One solution to this is to make enemies dumb.  Dumb enemies allow the players to choose who will be attacked.  The barbarian bangs on his shield and waggles his genitals at the harpies--they're guaranteed to attack him next turn.

Another solution is to make enemies slow (this is often a good way to make boss encounters escapable).  Slow enemies allow the party to retreat wounded party members.

This isn't a flaw.  Yes, it makes the encounter easier, but more importantly, it gives the players more control and more options.  You can balance it out by having the enemy deal more damage.

Intelligent enemies with a high damage output can (and should be) especially threatening.  You'll have to deploy them more carefully (and players will have to engage more carefully).

I highly recommend giving bosses attacks that hit multiple targets at once, such as everyone in melee range.

GLOG Rule: Focus Fire

You can never make more than two attacks against the same target in a single round.

Interesting Boss Mechanics

Look them up.

by Paolo Puggioni

Dragon

Usually accompanied by 1d6 drakencult barbarians, who will be riding the dragon if necessary.

I put a lot of bells and whistles on this dragon, but you can dial it back if you want.  Every round, just pick who it's gonna attack, and what wind-up attack it's going to do.  It only knows one spell, and it unlikely to use it except to mess with players.  Don't forget the Aura of Heat.

Level 10  Def as plate  Attacks x2 1d12
Fly fast  Int 10  Mor 6

Gold Sense - Dragons always know if something has been taken from their hoard.

Aura of Heat - Anyone who ends their turn adjacent to a dragon takes 1d6 fire damage.

Spellcasting (MD 3) - control fire

Wind-Up Attacks

At the end of each turn, you announce the one that will occur at the end of the next turn.  You cannot use the same wind-up attack twice in a row.

Fire Breath - 4d6 fire damage, 50' cone, Dex for half.
Smoke Exhalation - As fog.
Wing Flap - Unsecured objects/creatures will be blown 50' away.  50' cone.
Pin - Grapple target, bite them in half next turn (2d12 damage and +4 to hit).

Combat Start

Roar - Save vs terror.  Free action.

When Bloodied

The earth itself casts heat metal is cast on 1d3 metal objects.  (Whatever will make life hardest for the players.)  Free action.

Upon Death

All fires in 1 mile extinguish, and cannot be relit for 24 hours.

Dragon Tactics

Basically, just remember that dragons can fly and have little incentive to fight to the death.  They'd rather stay in the air and make strafing runs (fire breath, graps, fly-by attacks).  They can drop objects on the party if they need to.  Most dragons don't mind starting forest fires.

Dragons in their lairs are easier, since they must fight on the ground.  However, their lairs usually have loops (dragons hate getting cornered) and more drakencult barbarians.  And of course, getting stuck underground without any light will probably present some problems, too.

And lastly, remember that dragons are just as smart as we are.  They will use their abilities to the fullest.