We Can Improve It, We Have The Technology!
These monsters have been "improved" with a template.
Hey DMs: are you running out of monsters? Have your players read every book you have? Can they quote a monster's AC after you give the first sentence of it's description? If so, then you might want to try modifying monsters.
Many players modify monsters too. If you are a Wizard or Sorceror with a Familiar, a Druid or Ranger with an Animal Companion, or a Paladin with a Special Mount, you need to learn how to modify monsters!
The first and most important rule of modifying monsters as a DM is the following: as a DM, ECL doesn't matter!
As explained in the previous section, ECL determines how much XP a character needs to gain a level, and what sort of adventuring party a character should be in. These aren't things that matter to monsters that the players are supposed to fight. Instead, a DM has two other levels to pay attention to:
- Challenge Rating: Every monster has a Challenge Rating, or CR. Roughly speaking, a monster's CR is the level at which a character should be to have a 50% chance of defeating it alone. This also means the monster has a 50% chance of defeating the player! This is why it is normal for a party of four adventurers to fight a monster of a CR equal to their level. After fighting four such monsters in a row, the party's resources (the Fighter's Hit Points, the Wizard's Spells) should be nearly spent. By spreading out resources over the four party members, the adventuring party can fight things that might kill one of them on their own.
As a DM, there are two things you use CR for: experience points, and treasure. Page 38 of the Dungeon Master's Guide tells you how many experience points players get for defeating a monster of a specific CR, while the section starting on page 52 tells you how to randomly roll the standard treasure for a monster of that CR.
- Encounter Level: Let's say you want the party to fight more than one monster at once. How do you figure out how many? In order to determine when an encounter is an appropriate challenge for a party, you use Encounter Level. If the party's average level is equal to the Encounter Level, then that encounter is a good, challenging fight for the party. Page 49 of the Dungeon Master's Guide tells you how to calculate the Encounter Level for many different possible groups of monsters. It seems complicated, but most of it is based on a simple formula: When you double the number of monsters, you add two to the Encounter Level. This is because even if you have a lot of monsters on the table, if they're all very weak compared to the players then they won't be as much of a challenge. Double the monsters is not double the challenge.
So now you've got an Encounter Level and Challenge Rating in mind, how do you improve monsters to meet it? In general, there are four ways monsters improve:
- Advancing Hit Dice: Each monster has an Advancement: entry. For our friend the Vrock, this entry reads 11-14 HD (Large), 15-30 HD (Huge). What does this mean? When you Advance a monster's Hit Dice, you add more Racial Hit Dice to the monster. It's like leveling up in the monster's "class". The Advancement entry tells you the max level for the "class" (30 in this case), and whether the monster's size increases as it levels up (more on this later).
- Gaining Class Levels: A monster can also multiclass into a normal character class. In the above section we talked about monsters becoming PCs, here we talk about monsters becoming NPCs. A few of the rules for this are different. Some monsters have Advancement: By character class, which means that they can't ever gain any more Racial Hit Dice, and they only advance this way.
- Gaining a Template: Templates are instructions for modifying monsters. A template can change everything about a monster, or it can change almost nothing at all. A few very weird templates even can be applied to things that aren't monsters!
- Being Modified By a Class Ability: This is what Wizards do to their Familiars, and Druids do to their Animal Companions. Almost like a template, these class abilities modify the monster's stats. Some class abilities give monsters Bonus Hit Dice. It is important to remember that Gaining Bonus Hit Dice is not the same as Advancing Hit Dice. In particular, Bonus Hit Dice do not make a monster increase in size.
We're going to go through these options one by one and talk about how they work.
Advancing Hit Dice
When a monster advances in hit dice, it gains more Racial Hit Dice. Like the Racial Hit Dice it already had, these carry the Features of its Type, so its Base Attack Bonus, Base Save Bonuses, Skill Points, and Feats all increase. The monster also gains an increase to an ability score when its total Hit Dice reach a multiple of four, just like characters do. If you're advancing a monster, feel free to change where it put its Skill Points and Feats based on what you think it should have. Since these new Hit Dice are Racial Hit Dice, they increase Saving Throw DCs for the monster's Special Attacks.
As mentioned, Advancing in Hit Dice can also cause a monster to increase in size. For example, if you want a Vrock to increase to 15 Racial Hit Dice, you have to increase its size to Huge. When a monster increases from size due to Advancing in Hit Dice, its stats change according to the table on page 291 of the Monster Manual. The monster's Str, Con, Dex, natural armor, and natural weapon damage all might change, and the change in the monster's size will change its size bonus/penalty to AC and attacks. Note that the table on page 291 is only used for Advancing in Hit Dice, unless otherwise mentioned. In particular, if a monster increases in size some other way, such as from the Enlarge spell or a Template, it does not gain these bonuses to its stats. Many templates that increase size will direct you to use this table for ability adjustments, but this is not universal.
You can also make the monster's ability scores better in another way. When you advance a monster, you can declare that it is no longer completely average. Instead, you can give it the Elite Array or the Nonelite Array. The Elite array is 15, 14, 13, 12, 10, 8, while the Nonelite Array is 13 12 11 10 9 8. In either case you can rearrange these scores as you like, they don't have to stay in order. As you can see, the Elite Array represents a monster that it more powerful than normal (with the exception of one weakness), while the Nonelite Array is about equal in power, but more specialized. Once you have chosen an array, you apply the monster's racial ability score modifiers to find its final ability scores.
Once you have chosen how to Advance the monster, you need to calculate it's new CR. This is based on the number of Hit Dice you added. Some Hit Dice are more powerful than others: we've noticed that the Vrock has very nice Hit Dice, while undead have much less powerful Hit Dice. Because of this, different creature types get different amounts of CR from advancing in hit dice. If your monster is an Aberration, Construct, Elemental, Fey, Giant, Humanoid, Ooze, Plant, Undead, or Vermin, it gains one point of CR for every four hit dice it advances. If the monster is an Animal, Magical Beast, or Monstrous Humanoid, it gains one point of CR for every three hit dice. Finally, if the monster is a Dragon, or an Outsider (like the Vrock), it gains one point of CR for every two hit dice it advances.
Some other factors need to be considered before you reach the monster's final CR. If the monster increased from Medium to Large, you need to add an additional +1 to the CR, as Large creatures can be much more powerful than Medium creatures. If you used the Elite Array, you also need to add +1 to the CR. The Nonelite Array can be applied without changing the CR.
For example, suppose we increased our Vrock to 16 HD. The Vrock has gained 6 hit dice, and since it is an Outsider this means that its CR goes up from 9 to 12. It also increased from Large to Huge, but since it was already Large this does not increase its CR. If you wanted to give it the Elite Array that would be an additional +1, making its CR 13.
Gaining Class Levels
Giving monsters class levels as a DM follows many of the same rules as giving them class levels as a player. The process remains much like multiclassing, with the new Hit Dice from classes added on top of the old Racial Hit Dice. A few details are important to remember, though:
Monsters (and all NPCs, since they're monsters too) don't roll ability scores. Instead, monsters use an array. Monsters with class levels aren't average. In fact, in most cases, you should use the Elite Array (as described earlier) for monsters with class levels. Monsters with class levels can use the Elite Array with no increase in CR. If a monster is in an NPC class like Warrior, Adept, or Expert, then you can consider using the Nonelite Array instead. Monsters with class levels should never use Average Scores.
Monsters don't have Wealth, they have Gear. The Wealth-by-Level guidelines are for PCs. NPCs and Monsters have Treasure, or Gear. If a monster has class levels it should have the same gear as an NPC of its CR. NPCs have gear values given on page 127 of the Dungeon Master's Guide. These values are about triple the standard treasure for a monster of their level. In general, a monster gets its treasure entry in addition to its gear, which means a monster with class levels has a lot of treasure. If your party is going to fight a lot of monsters with class levels, try to balance out the increase in treasure by having them fight a few traps or monsters with no treasure, like golems. Note also that you can change the treasure rewards around a little as long as you keep the appropriate average, but that a monster with class levels is expected to have at least the NPC gear in order to be as effective as an NPC of their CR.
Sometimes class levels will increase a monster's CR, sometimes they won't. The rules for this are the rules for Associated and Nonassociated Class Levels, and they are on page 294 of the Monster Manual. The purpose of the rules for Associated and Nonassociated Class Levels is as follows: sometimes a class is straightforwardly good for a monster. If your monster likes to hit things with its claws, a level of Barbarian will make it better at doing so. On the other hand, a CR 15 monster with a single level of Wizard isn't much different from a monster without that level, since first level Wizard spells don't matter very much when you're 15th level. In general, a class is Associated if it contributes to the monster's strengths. In particular, if the monster relies on its fighting ability, Barbarian, Fighter, Paladin, and Ranger are associated. If the monster relies on sneaking up on its enemies, Rogue and Ranger are associated. If the monster can cast spells, the class that it casts spells as is associated. Note that if a monster that casts spells takes a level of a class that casts the same sort of spells, the levels stack for determining their spellcasting. For example, a Rakshasa casts spells as a seventh level Sorceror. A Rakshasa Sorceror 1 would then cast spells as an eighth level Sorceror, while a Rakshasa Wizard 1 would cast spells as a multiclass seventh level Sorceror/ first level Wizard. The Sorceror level is associated, the Wizard level is nonassociated. For classes not listed here, compare them to the listed classes to figure out where they go. For example, the Blackguard is a melee class, so a monster that fights in melee (like a Frost Giant) would treat it as associated. Interestingly enough, some monsters can qualify for prestige classes with just their Racial Hit Dice alone!
Once you know whether a class is associated or nonassociated, you calculate the CR as follows: if the class is associated, every level in it adds 1 to the CR. For example, a Vrock Fighter 2 is CR 11, since Fighter is an associated class for a melee monster like the Vrock. If the class is nonassociated, every two levels add 1 to the CR. For example, a Vrock Wizard 2 would be CR 10, since Vrocks don't have racial Wizard spellcasting.
Eventually, a monster has so many levels in a nonassociated class that the class is a bigger part of how the monster fights than the monster's stats! When a nonassociated class level is equal to the monster's Racial Hit Dice, all further levels in that class are treated as associated. Going back to our Vrock example, let's say the Vrock has gotten up to level 10 in Wizard. These levels are equal to his Racial Hit Dice, so they are still nonassociated and the Vrock's CR is 14. When the Vrock gains its next level in Wizard, that new level is associated, so the Vrock now has CR 15, and will gain one more CR for each additional level of Wizard.
The Monster Manual also says that NPC classes (like Adept or Warrior) are always treated as non-associated. However, the DMG says that a monster with an NPC class should just subtract one from the CR it would otherwise gain from that class. It is important to remember that CR is always an estimate. Since you have two conflicting standards, you should use both of them for advice and try to find a middle ground that accurately represents the challenge the monster provides.
Gaining a Template
A template is a list of instructions for modifying a monster. In general, templates are self-explanatory: if you know how monsters work and you follow the instructions you should be able to apply the template correctly. However, templates use a few sorts of special terminology and rules:
Inherited and Acquired Templates: In 3.5, every template should say whether it is an Inherited or Acquired template. Inherited templates like Half-Dragon are templates a creature is born with, while Acquired templates like Vampire are gained later in the creature's life. A creature can have more than one template. If you apply multiple templates to a creature, the Inherited templates need to be applied before the Acquired templates, for obvious reasons.
Templates have prerequisites: Just like feats and prestige classes, sometimes monsters need to have certain attributes to have a template. Usually this will be listed in the first few sentences of the template. For example, the Vampire template says that it can be added to any humanoid or monstrous humanoid creature. This means that since Ogres are Giants, an Ogre cannot be a Vampire.
The Augmented Subtype: Some templates change a creature's type. Every Vampire is Undead, while every Half-Dragon has the Dragon type. However, this doesn't usually mean that you have to change all of a monster's Racial Hit Dice when it gets a template. Unless the template says otherwise, if a template changes a creature's type gains the Augmented(Former Creature Type) subtype. For example, a Half-Dragon that you based off a Brown Bear goes from being an Animal to a Dragon(Augmented Animal). The Augmented Subtype means that, while the creature gains the Traits of its new Type, it keeps the Features of its original Type. So a Half-Dragon Brown Bear would have the same Base Attack Bonus as a normal Brown Bear, and would not gain the Base Attack Bonus of a creature of the Dragon Type. Even if a template says it changes a creature's Hit Dice, those changes only apply to Racial Hit Dice unless the template says otherwise. In particular, while some types of Undead change all of a creature's Hit Dice, including those gained from classes, (Vampire and Lich are both examples) if the template does not say it changes Hit Dice from classes, it does not do so.
Size Increases: Some templates change a creature's size. If a template changes a creature's size, its size bonuses and penalties change according to the table on page 291, as does its natural armor. However, the creature's Str, Dex, and Con do not change unless the template explicitly says they do.
Save DCs and other effects based on Hit Dice: Remember how when we discussed Racial Hit Dice, we said that abilities a monster has based on Hit Dice are only based on Racial Hit Dice, just like a Paladin's Smite is only based on Paladin levels? Well templates are different. Instead of being like class abilities, templates are like feats: they can be added on to many different monsters with different Racial Hit Dice. Because of this, when a template gives a formula based on Hit Dice, like a Save DC, it is based on the creature's total Hit Dice, including class levels, unless it specifically says it only applies to Racial Hit Dice. This means that when the creature gains class levels, these abilities will increase in power.
Templates list their effect on CR and LA. In both cases this should be quite straightforward. If a template says LA --, that means the template makes the character unplayable.
Being Modified By a Class Ability
Like templates, class abilities will in general say what attributes of a monster they change, and if you're savvy enough to how monsters work you should understand how to apply them. Some class features, like the Druid's Animal Companion and the Paladin's Special Mount, gain bonus Hit Dice. As mentioned before, bonus Hit Dice do not make a creature increase in size. However, they are Racial Hit Dice. Bonus Hit Dice have whatever Features the class ability says they have, defaulting to those of the base creature's Racial Hit Dice. Some other class features like the Wizard's Familiar instead say that for purposes of effects relating to Hit Dice you should treat the creature's Hit Dice as higher. These are not actually bonus Hit Dice, and instead refer to spells, like Sleep, that have different effects on creatures with different numbers of Hit Dice.
Many class abilities say that a creature must be a normal creature of its kind. This means that a creature modified by any of the other methods in this section (including the class abilities of other classes) is not an eligible choice.