Monday, January 12, 2015

Monster Building Walkthrough: Upgrading the Hill Giant

Last week, we covered the process of building a monster from scratch. This week, I'd like to talk about the process of upgrading an existing monster from the Monster Manual.

We're going to use the Hill Giant as an example because it's a pretty straightforward monster without any variants. More specifically, let's construct a Hill Giant Chieftain - an upgraded version of the regular monster - for use as a "boss" monster in a Hill Giant-themed adventure. We'll call her Angrboda.

Take a second to pull out the Hill Giant stat block from your Monster Manual (p. 155), or from the Dungeon Master's Basic Rules.

D&D 5E's version of the Hill Giant is as dim-witted
as ever. It doesn't matter how dim-witted it is
when it's coming at you with a club, though!
Artist: Justin Sweet
First, we'll have a look down the Hill Giant to see where its Challenge Rating comes from.
The Hill Giant has no traits that affect its CR, so to calculate defensive CR we simply input hit points (105) and read down the column of the table on page 274 of the DMG to discover that this corresponds to a defensive CR of 3. Since our AC value of 13 matches that exactly, a Defensive CR of 3 it is!
Next we check on offensive CR. Since multiattack allows for two Greatclub attacks, we double the damage value of 18 to 36, giving us a base offensive CR of 5. However, since the Hill Giant has an attack bonus of +8, two higher than the CR 5 average of 6, we bump that up to an offensive CR of 6. We can mostly ignore the Rock attack because CR is evaluated based on the strongest attack options - Rock mostly gives the Hill Giant options for when melee isn't possible.
Averaging offensive and defensive CR, we find that the Hill Giant ends up at a CR of 4.5, which we round up to 5.

What can we learn from this? Well, the Hill Giant is something of a glass cannon. It's capable of dishing out a lot of damage for its CR but it's easy to hit and will go down quickly if targeted by attacks. While we may want to fiddle with that, ideally Angrboda will have characteristics similar to those of the baseline Hill Giant - just with a higher overall CR. In this case, we'll aim for about 7 - about as strong as a Stone Giant but not as powerful as Frost Giants.

We'll try three different methods of modifying Angrboda's CR.
  • Directly modifying the Hill Giant's attack and defense values is the easiest and simplest way to upgrade a monster.
  • For those that enjoy being faithful to the system, changing Angrboda's raw ability scores, hit dice, and equipment will produce more accurate upgraded values while still being fairly simple.
  • Finally, for the highest level of "realism" and significant additional abilities, we'll talk about adding class levels to a monster. In this case, the Battlemaster Fighter grants some neat combat tricks that'll make fighting Angrboda more exciting.

First, let's simply bump the Hill Giant up to a Chieftan level by increasing raw statistics. To stay the closest to the original monster, we'll bump Offensive CR and Defensive CR up by two each, producing an overall CR increase of two.
To give Angrboda a Defensive CR of 5, we simply look at the table on page 274 of the DMG. A defensively CR 5 monster has 131-145 hit points (we'll use 140 for simplicity) and an AC of 15. Easy!
Offensive CR is similar. An Offensive CR 8 monster deals 51-56 (let's say 54) damage on each attack with a bonus of +7. Although this is lower than the Hill Giant's original bonus of +8, we can simply say Angrboda is a little less accurate but with more powerful blows - or bump it up to +8, because an increase of 1 in attack bonus doesn't change CR. We'll split her damage between her two greatclub attacks, saying that they deal 27 damage each. What about the Rock attack? It's a little less powerful than two Greatclub attacks, so we can eyeball it at +8 with perhaps 40 damage - or just use it as is, since it's not the most powerful attack in the first place. Perhaps this version of Angrboda is much better with her club than with a rock.
The Defensive and Offensive CRs of 5 and 8 average out to 6.5. Rounding up, this gives us exactly the 7 that we wanted! With the table in the DMG, this sort of conversion can be done in a minute or two. It might not hold up under pressure (What if this Angrboda scores a crit- perhaps roll 6d8 on top of her static damage?), but it works in a pinch or when you don't care about a monster other than its raw stats.

When I googled "female giant," this is one of the only
appropriate pictures I could find. Memo to the D&D Team:
giants deserve gender equality too!
Artist: Ralph Horsley
The next method produces a more "realistic" monster by making in-system adjustments. We’ll give Angrboda a powerful weapon, bump up her Strength score to increase attack power, and add hit dice and armor to increase defense. All bonuses a powerful Hill Giant might have available, right?
We can bump up Defensive CR by adding two hit dice, bringing the chieftain to a HP total of 126 (12d12+48). Remember, each additional HD adds the Constitution bonus to HP as well. Let's also add armor - chain mail and a shield seem to be appropriate, and patchwork chain mail might be something a Hill Giant would scavenge. This supersedes natural armor and brings her AC up to 18. Consulting the DMG table, this grants a defensive CR of 6, which seems acceptable for now.
Next, we can give Angrboda a little boost in attack power. She now needs a one-handed weapon (because of her shield), so let's give her a flail - flails are badass and seem like something a Hill Giant might use in combat. To increase her attack power, we can bump her Strength to 24, with a +7 bonus. This is two higher than her previous Strength, so this adds +2 to the attack and damage of both of her attacks. Though the CR changed, the proficiency bonus between CR 5 and 7 is the same, so we can ignore that factor. She'll deal 20 damage on each of her two hits with a +10 bonus, so we can consult the table and calculate an offensive CR of 8. Although there's no good weapon upgrade for the Hill Giant's Rock, Angrboda's Strength increase makes her Rock attack go to +10 at 23 (3d10+7) damage. As discussed above, this doesn't affect CR but gives Angrboda a backup ranged weapon.
8 and 6 perfectly average to make a total CR of 7 - exactly what we're looking for! Additionally, now Angrboda feels more "realistic" - each of her improvements come from something logical.

Finally, let's walk through the process of granting class levels to a monster. In this case, we're giving Angrboda three levels of the Fighter class to let her use some Battle Master maneuvers. With the ability to intimidate characters, push them around, and attack in retaliation, she'll come off as a dangerous threat. In this case, class abilities will essentially take the place of upgrades to Strength in terms of damage.
When changing defensive CR, let's keep the Chain Mail and Shield. A flail seems a flavorful addition to a skilled Hill Giant warrior, and the armor helps emphasize that Angrboda is a skilled combatant. In terms of hit points, we've got to consider that she gets three new d12 hit dice from her Fighter levels (monster hit dice are based on size, not class). This gives her a HP total of 136 (13d12+52)... but wait! There is one defensively-focused Fighter ability - Second Wind. As a third level Fighter, she'll be able to regain 1d10+3 hit points as a bonus action. Since she likely won't use her bonus actions for anything else, this essentially adds a guaranteed ~9 hit points to her total. With an effective HP total of 145 and an AC of 18, she's at a defensive CR of 6, which seems fine.
In terms of offense, Angrboda's Fighter levels have a more substantial impact. For her third level Combat Superiority ability, let's pick out the Menacing Attack, Pushing Attack, and Riposte maneuvers. This will let her terrify her enemies, push them around, and return ineffective attacks. - all very flavorful for a giant warrior. Note also that Menacing Attack and Pushing Attack also works with Angrboda's Rock attack - who wouldn't be terrified when a Hill Giant chucks a boulder at you?
For monsters with a variable damage output, the DMG recommends we consider their average damage over three rounds. Action Surge allows a second Multiattack on one turn (adding a straightforward 18 to her damage on that turn), but the maneuvers are more complicated. Menacing Attack and Pushing Attack won't boost her damage beyond the 1d8 superiority die, but Riposte allows an extra attack on a reaction, pumping damage significantly. Let's assume that in two of those three rounds, she uses Riposte to make an extra attack. We'll calculate damage over three rounds as follows: 10*18 (six "normal" flail attacks, two from action surge, two from riposte) + 18 (4d8 from superiority dice) = 198 damage, which averages to 66 damage per round. Whoa! That's in line with the expected damage for CR 10 offensively.
We may have to downgrade Angrboda's offensive abilities a bit. Let's give her a mace instead of a flail - this will cause her attacks to deal only 15 (3d6+5) damage on a hit (remember that Huge-sized weapons have thrice the number of damage dice). This decreases her average per-round damage to just 56, which with a +8 bonus to attack gives her an Offensive CR of 8. Perfect! This averages to a total CR of 7 - exactly where we want it.

Today, we've been through three different methods of upgrading a basic monster - changing base statistics, modifying ability scores and equipment, and adding class levels. Next week, we'll discuss the process of building a spellcasting monster - one of the more complicated feats when DMing D&D 5E!

EDIT: Arsonor in the comments asked for the finished stat blocks of our revised monster. Here you go, Arsonor!

Angrboda, Hill Giant Chieftain (Version 1)
Use Hill Giant stat block, except for the following changes
Armor Class 15
Hit Points 140
Greatclub. Melee Weapon Attack: +8 to hit, reach 10 ft., one creature. Hit: 27 bludgeoning damage.
Challenge 7 (2,900 XP)

Angrboda, Hill Giant Chieftain (Version 2)
Huge giant, chaotic evil
Armor Class 18 (chain mail, shield)
Hit Points 126 (12d12+52) Speed 40 ft. ----------------
Str 24 (+7) Dex 8 (-1) Con 19 (+4) Int 5 (-3) Wis 9 (-1) Cha 6 (-2)
Skills Perception +2
Senses passive Perception 12
Languages Giant
Challenge 7 (2,900 XP)
Multiattack. Angrboda makes two flail attacks.
Flail. Melee Weapon Attack: +10 to hit, reach 10 ft., one creature. Hit: 20 (3d8+7) bludgeoning damage.
Rock. Ranged Weapon Attack: +10 to hit, range 60/240 ft., one target. Hit: 23 (3d10+7) bludgeoning damage.

Angrboda, Hill Giant Chieftain (Version 3)
Huge giant, chaotic evil
Armor Class 18 (chain mail, shield)
Hit Points 136 (13d12+52)
Speed 40 ft.
Str 21 (+5) Dex 8 (-1) Con 19 (+4) Int 5 (-3) Wis 9 (-1) Cha 6 (-2)
Skills Perception +2
Senses passive Perception 12
Languages Giant
Challenge 7 (2,900 XP)
Second Wind (Recharges after a Short or Long Rest). As a bonus action, Angrboda can regain 1d10+3 hit points.
Action Surge (Recharges after a Short or Long Rest). On her turn, Angrboda takes an additional action.
Combat Superiority. Angrboda has four d8 superiority dice, which she regains after a short or long rest.  She can spend these superiority dice on her maneuvers, and cannot use more than one maneuver per attack.
  • Menacing Attack. When Angrboda hits a creature with a weapon attack, she can expend one superiority die. If she does, she adds the superiority die to the attack's damage roll and the target makes a DC 16 Wisdom saving throw. If it fails, it is frightened by Angrboda until the end of its next turn.
  • Pushing Attack. When Angrboda hits a creature with a weapon attack, she can expend one superiority die. If she does, she adds the superiority die to the attack's damage roll and the target makes a DC 16 Strength saving throw. If it fails, it is pushed up to 15 feet away from Angrboda.
  • Riposte. When a creature misses Angrboda with a weapon attack, she can spend a superiority die as a reaction. If she does, she makes a melee weapon attack against the creature, adding the superiority die to the attack's damage roll on a hit.
Multiattack. Angrboda makes two mace attacks.
Mace. Melee Weapon Attack: +8 to hit, reach 10 ft., one creature. Hit: 15 (3d6+5) bludgeoning damage.
Rock. Ranged Weapon Attack: +8 to hit, range 60/240 ft., one target. Hit: 21 (3d10+5) bludgeoning damage.


  1. Great post, very detailed. Even if I never use 5e, I can still appreciate the insight and effort you've put into this. It's refreshing. Interesting that merely changing the weapon can make the difference between CR8 and CR10. I'm rather curious how they attempted to balance creating spellcasters.

    1. They leave it very vague for spellcasting, but you can get the best idea by using the 2 rules shown above 1) Average damage over three rounds and 2) Assuming the most damage possible given the spell selection and slots available. With spellcasters that can vary depending on prepared spells. If you do a control caster with few or no damage spells, it's going to come out as a lower CR than a dedicated War Caster who drops a fireball every round.

    2. Thanks for the comment - positive feedback inspires me to write more!
      I think the huge d6/d8 weapon difference came mainly from the Multiattack feature - lots of monsters in 5E deal low weapon attack damage but make up for it with many attacks. I think this is so they can spread it out between different PCs. The Fighter's ability to add additional attacks from Action Surge and Riposte makes a difference here too.
      As for spellcasting, redkat is right in that there aren't tons of guidelines for making a spellcasting monster other than the general attack/defense numbers. I'll spend some time next week talking about sifting through the mass of spells in 5E and finding the ones that actually contribute to CR.

  2. I love this. I just need to find a way to work her into my game...

    I hate to ask, but since I'll now be following your posts... if you continue the series, posting the finished stat block is helpful. I am copying and pasting them into my files for the future.

  3. This comment has been removed by the author.

  4. Good article. Koga305, I appreciate the effort here. I would like to see more of these broken out like that. I am tinkering with a Bugbear Chieftain with all of his 10 HD replaced by Fighter levels. I am struggling to work out the final CR. This article has helped. Thank you.

    Here is the boss idea: Bugbear Chieftain, 10 level Battlemaster Fighter. Fighting style = Two Weapon Fighting. Feats = Dual Wielder and Sentinel. Maneauvers = Riposte, Precision Attack, and Tripping Attack. The technique is called Brutal Assault = trip an opponent and then go to town on them while they are prone with many attacks.

    This is meant to be a Threatening encounter around CR10. I thought he might have at least two common Bugbears with him. What do you think? Any advice?