How much do I need to prepare?

[Malaqai]

I'm going to be DMing my first campaign in a week. I have developed a homebrew setting that I'm happy with, but I'm a little bit anxious about the encounters themselves. What is the best way to go about populating the world with encounters for the PCs?

[Red Fel]

I'm going to be DMing my first campaign in a week. I have developed a homebrew setting that I'm happy with, but I'm a little bit anxious about the encounters themselves. What is the best way to go about populating the world with encounters for the PCs?

One of the first rules of DMing is the same as one of the first rules of warfare - no plan survives an encounter with the enemy (here, the players). The trick is not to prepare specifics, but generalities.

One device that's frequently recommended is to have a notebook full of standardized character and encounter concepts. Slap together some quick stats for any kind of person the PCs might meet - traveling merchant, town blacksmith, captain of the guard, lesser noble, etc. Jot down a few concept notes for different scenarios that could spin off of each.

Next, when designing the world, figure out the different parts of the world, and what players are likely to encounter. In essence, it's like a random encounter table, only less random. Again, make your little cue cards of each type of creature, with scenario notes as to motivation, hostility, etc. An alternative is to do away with random encounters altogether, but it can be hard to plan out each battle and social scenario.

So, for example, in a small town you might have two or three characters, with a few scenario notes for each. The town mayor, for example; come up with some possible plot hooks depending on how the PCs play - maybe there's a wolf infestation, or a murder mystery, or he needs a delivery - possible attitudes or relationships - maybe one of the PCs offended the innkeeper who happens to be his brother, or maybe he has a positive disposition towards Elves - and a few amusing possible quirks - maybe he has a speech impediment, or walks with a limp, or something. The players may seize on anything, and if they fall in love with the adorable daughter you wrote in just on a whim, you've got a plot motivator. Throw in some generic NPCs for the village; in the surrounding areas, add a few notes on wolves, orcs, and a traveling gnomish circus. For the forest region, you might have five or six elven characters - again, with encounter and scenario notes - an angry monkey, some lumberjacks, a starving rust beast, and so forth.

Just some ideas. A major part of DMing is being overprepared; the rest is learning how to wing it when you (inevitably) learn that those preparations were insufficient.

[Subaru Kujo]

Another thing on what Red Fel said. Start (comparatively) small in encounter size (unless of course, it's meant to be something the PCs aren't supposed to be fighting head on). For instance, I once started off an encounter at level 2 with 3 ghouls. The reason I started with that few is if your 4 man party has 2 people get paralyzed, it's not going to end well if you suddenly put the other 3 ghouls you had in waiting on the board.

The point is, it's easier to not put things on the board, than it is to take them off as far as player suspicions go. Granted, your group might understand that you overshot the encounter difficulty, but I generally don't like to take that chance, you know?

[Elkad]

Make sure you have a secondary plan. Build an your encounters, throw some plot hooks around. And then assume there is a good chance your players will ignore the Endless Swamp full of carefully crafted encounters you have dangled in front of them, and the Wicked Woods you had some vague ideas for once they gained a few levels, and head for the Dragon Mountains instead, just because the name looked cool on the map.

Some encounters you can just move, reflavoring on the fly. The goblin camp at the edge of the swamp could be called the "wild elf camp" on the edge of the woods instead, and played exactly the same.

But you need a plan for what's out there in every direction, and maybe an encounter designed to turn the players around. 2nd level party heads off to the Dragon Mountains. You don't want them there. Give them a nice fight with too many orcs (several per player). Mid-fight, a green dragon swoops down, dissolves most of the orcs (go all out, roll a BIG pile of dice. Throwing 18d6 damage right in front of a 20hp player WILL get his attention, especially if you obviously aimed the cone to miss him). Dragon looks at the PCs and says "They were warned to stay off my mountain. Now you have been warned as well", as he snatches up a gooey orc to munch on and flies away. The players get to clean up the rest of the fight (or make a truce with the orcs to all escape together), and hopefully will take the advice of the clue-by-four you just smacked them with.

[Trasilor]

I'm going to be DMing my first campaign in a week. I have developed a homebrew setting that I'm happy with, but I'm a little bit anxious about the encounters themselves. What is the best way to go about populating the world with encounters for the PCs?

Red Fel is correct - having NPCs is always a good starting point.

But there are couple of things you should consider:

• Figure out what kind of game your players are looking for. Some want the railroad, others the sandbox. Other examples include: combat, exploration, investigation, etc. (I had one friend run a mist game where giant walled cities kept the encroaching doom away - sort of like a survival game)
• Work it backwards - if you give a plot hook - you are giving them the End Goal (rescue a princess, get the jewels, defend farm from bandits). Think of different ways the goal could be accomplished
• Begin the adventure in combat - A great way to get into the game is to be immersed immediately (traveling home from the local festival and come across bandits attacking a merchant...)
• Be prepared to wing it - it will eventually happen.
• Be honest with your players - if you need 5 min to prep - let them know you need 5 min.
• Take notes. During the game, plot hooks may arise without you even realizing it (this usually happens when the players says something you weren't expecting and you go yeah, that is an awesome idea to yourself).
• Have fun. You are playing a game too

[Bronk]

Red Fel is correct - having NPCs is always a good starting point.

But there are couple of things you should consider:

• Figure out what kind of game your players are looking for. Some want the railroad, others the sandbox. Other examples include: combat, exploration, investigation, etc. (I had one friend run a mist game where giant walled cities kept the encroaching doom away - sort of like a survival game)
• Work it backwards - if you give a plot hook - you are giving them the End Goal (rescue a princess, get the jewels, defend farm from bandits). Think of different ways the goal could be accomplished
• Begin the adventure in combat - A great way to get into the game is to be immersed immediately (traveling home from the local festival and come across bandits attacking a merchant...)
• Be prepared to wing it - it will eventually happen.
• Be honest with your players - if you need 5 min to prep - let them know you need 5 min.
• Take notes. During the game, plot hooks may arise without you even realizing it (this usually happens when the players says something you weren't expecting and you go yeah, that is an awesome idea to yourself).
• Have fun. You are playing a game too

I would also add: try to reward your players for thinking outside the box. That's part of what makes the game fun, and especially so for those who come up with great ideas. As long as the idea doesn't violate or try to get around any rules or whatnot, anyway. My suggestion is to try not to give a flat out 'No,' or 'You can't do that', instead let them try then explain what does or doesn't happen... now it's not a refusal on your part, but part of the mystery. The explanations they come up with may even be better than what you came up with too! That is the fun of role playing!

[Darrin]

I'm going to be DMing my first campaign in a week. I have developed a homebrew setting that I'm happy with, but I'm a little bit anxious about the encounters themselves.

The CR system is a good starting point. It's also weighted in favor of the players to begin with (but with the caveat that 1st-level encounters tend to be a crap-shoot). As you get a feel for how your players optimize and how they utilize their resources, you can start adjusting the CRs up or down.

The players tend to think of encounters as pinatas full of XP and GP, and to be fair, this is the "default" mode for D&D. Nothing wrong with that, mind you, and it works very well for most hack-and-slash campaigns. But there are two things you can do to add more depth:

1) Goals and motivations. Can you give the monsters a specific goal other than "stand still and soak up damage"? "Defending their lair" is the default mode, but for most practical purposes is the same as pinata mode. Are the monsters fighting to obtain a particular resource? Does the resource have any value to the PCs, or just to the monsters? Is there a local faction supporting the monsters? Are the monsters defending something other than their home? Are they fighting a holding/delaying action so that something else can happen or get away?

2) There are at least three ways to overcome an obstacle:

a) Violence. Default mode. HP is the currency of narrative control, eliminate something's HP and you control what happens to it in the story.

b) Specialized Skill. Thief picking locks is a good example, but this also includes magic (wizard casts knock).

c) Social engineering. This is not "bard rolls bluff/diplomacy" (which would actually be the previous category), but rather information-brokering. Passwords to bypass guards, magic portals, or activating magic items. There's a secret passage to get around the lava chamber. Casting speak with dead on the corpse outside the room can tell you where the poison spikes are hidden. The dragon likes to collect vintage elven wines. If you talk to the blacksmith back at the village, he can tell you the ogres will be friendly if you offer them pumpkin pies.

Every encounter should have multiple methods to circumvent it. So put some thought into different ways for the PCs to get through an encounter, beyond just the violence option. This should apply to every creature, trap, or obstacle the PCs run into. Even something as simple as a locked door: chop it down, pick the lock, or find out who has the key?

The PCs will often come up with solutions you didn't anticipate. That's ok, they're just doing their job. Your job is to be flexible and adapt as best you can.

Another good principle to keep in mind: Don't be afraid to let the PCs win. Even if the BBEG turns into a cakewalk and the PCs get a lootgasm they didn't really earn... let them have it. The worst that can happen is your BBEG dies and the PCs get way more loot than you intended. The best thing that can happen is you've now got a springboard to introduce more challenges (PCs are now targets for revenge, for greedy merchants, for "noble causes", etc.). Trying to prop up an underpowered encounter save your pet BBEG/NPC/Plot has way too many pitfalls, and if you're too heavy-handed or overt about it, you wind up undermining your authority, which is your primary narrative currency.

What is the best way to go about populating the world with encounters for the PCs?

That's a complicated question, and depends a great deal on the style of your campaign. Dungeon crawl? Hack-n-slash? Political intrigue? Sandbox? Printed modules?

I like to start with a Big Event that is going to happen. You then have two sides: one that wants to make sure it happens, and one that doesn't. Break each side down into factions. To start with, just take every base class in the PHB and ask yourself, "How would an organized group of {x} feel about this Big Event?" You can put black hats and white hats on every faction to start with, but put some thought about each faction having a specific goal/motivation, and what might cause them to change sides. Start the PCs as working for a Patron that belongs to a particular faction. Then you give the PCs a "simple job", and they unwittingly get their hands on an artifact/macguffin that has a huge impact on whether the Big Event happens. The two sides then deploy factions to deal with the PCs getting the macguffin. The faction largely determines what sort of encounters they throw at the PCs: the Evil Necromancers For A Brighter Tomorrow send low-level undead minions to start with, then maybe a Wight flunkie as the PCs get stronger. Druids send in the Bear Cavalry. And so forth.

From there, I like to think of encounters have three sort of "difficulty settings":

1) Pinata mode. This is a straight-up slugfest, meatbag vs. meatbag. Nothing fancy, just a numbers game of whichever side can hack down the HPs to zero first.

2) Gimmick mode. Introduce a special ability or tactic that the PCs have to figure out how to neutralize or overcome. How do the PCs deal with invisibility? Poison? Fire resistance? Incorporeal? These tend to be more dramatic and challenging, as the antagonists have an advantage over the PCs, and the PCs have to use their creativity to swing the odds back in their favor. If the PCs are too dense to catch on, you can usually salvage the encounter by bringing in a faction with the "counter" to the gimmick. There's also a "2.5" mode where you pair up two complimentary gimmicks, such as magmins + iron golem, shocker lizards + shambling mound, or something with DR that hides inside an insect swarm.

3) Force multipliers. I tend to think of these as terrain features, but they can also be ongoing spell effects, combinations of tactics/equipment, status conditions, or just a few circumstance modifiers. The best example is probably a cracked pillar holding up a crumbling ceiling: shatter the pillar to bring the roof down on your enemies. Wall hangings = flammable? How does the enemy deal with reduced visibility and smoke damage? Can the battlefield be flooded? Was the party able to sneak in and get to the high ground first? I like to plan these out for encounters where the PCs are overmatched, but clever or well-prepared PCs can spot the force multipliers before the antagonists catch on. Tend to be higher on drama, but extremely unpredictable with high potential for PC death or TPK.

Some other thoughts: it's almost always a good idea to pair up mooks with bosses. Mooks by themselves are just bookkeeping: rack 'em up, knock 'em down. Add a miniboss, and the PCs have to decide who to concentrate on first. Nothing fancy, just slap on an extra HD/Fighter level, or don't change anything and give one of the mooks a distinctive feature: eyepatch, scarred face, red scarf, or whatnot. It also gives you an "out" if the mooks get in some lucky hits and the battle starts to turn against the PCs, the miniboss can take a dive, forcing mooks to "break morale" and run off, or vice versa. A miniboss that surrenders or gets captured is also a great way to feed "intel" to the PCs, information on possible force multipliers up ahead, a password to get past the guards, a secret door behind the throne room, etc. Big Bosses without minions get shafted by the action economy: if the boss only gets 1 turn before the entire party can concentrate their actions on a single foe, they rarely last longer than 2 rounds. Never let your BBEGs go up against the PCs entirely by their lonesome selves, unless the PCs have earned themselves a righteous curbstomp. Use summons, illusions, and haste/contingency effects to make sure your BBEGs can act more than once a round.

I like to throw in a few turncoats as well (what I like to call "Whedonesque switches"). The PCs finally close in on the BBEG, only the BBEG rips off his mask, explains in a very quiet voice how this doppelganger/polymorph/ice assassin ruse is about to go extremely pear-shaped in a moment, and then begs them for help against a trusted confidant, who may or may not be the real BBEG. Also extremely useful if the party has managed to completely FUBAR themselves into prison or onto an executioner's platform.

In a nutshell:

Expect the PCs to murderhobo everything and plan accordingly.

Be a good loser.

Respect player agency. If you need to railroad, explain why, and then tell the players when they will get back in the driver's seat.

Use the other players as a resource. They can run monsters, shopkeepers, royal servants, etc. Need a tavern? Jewelry Shop? Pirate crew? Temple of Healing? Scroll merchant? A village not on the map? If you don't have time to create it yourself, ask the players to create something.

[mashlagoo1982]

DnD, the game where everything is made up and the xp doesn't matter.

[atemu1234]

For the mission itself, have the NPC statistics, maybe a general combat plan (remember: they don't know the PCs, so don't pretend they do) and have the grids for the different areas. Have a couple notes on each of the areas, like what they look like, what search DCs might turn up, etc. Have copies of the character sheets (something I myself rarely do, mostly because my group levels up quickly thanks to me putting max encounters in, but when I do, it comes in very handy). Have a general plan for how the adventure should go, but don't railroad it. Also, make sure you have the NPCs (the specific ones, not the encounters) personalities down. PCs do stupid things, NPCs should react like a person in the real world would (maybe with slight differences, but not many).

[Malaqai]

Thanks for the input! What I'm considering right now is starting the PCs on a boat carrying merchants as well as supplies to a distant garrison. It turns out the merchants are agents of one of the factions of the setting who intend to hijack the boat. The PCs abandon ship (or are thrown off depending on how events proceed) and are set loose into the world with a few character plots to direct them. How does that sound for a first encounter?

[daemonvatis]

Your encounter idea sounds good. You do want to make sure you understand the characters' motives and personalities well enough to make sure that they will follow any given plot hook (evil characters don't care about starving orphans, some characters actually wouldn't respond to promises of wealth, etc.). Your players should cooperate with providing motives for their characters that fit your plan (maybe the evil character is on the run and figures that being in a good adventuring party will provide good cover) but it's an issue you should be aware of.

I wouldn't say you need to make stats for any NPCs (except maybe diplomacy and knowledge for plot-relevant ones). The DMG has stats for generic NPCs with PC classes on page 110. For skills, I usually assume that NCPs have no modifier for skills they wouldn't specialize in and a 4 or 5 +level modifier for skills they would specialize in.

I've actually found that treasure is the most difficult part to improvise on the fly. You might want to read over the relevant sections in the DMG. Just in general, the DMG requires a lot of reading but is your friend.

Also, encourage your players to entertain themselves/each other when you're busy throwing something together. Early in the campaign I was actually giving out XP for impressive dice towers so long as they weren't disruptive when I was trying to lead.

[Dornith]

I know this is going to sound like terrible advice but here it is:
Don't prepare much at all. Get the basic story outlined, have a few encounters in mind, a map of the area they will be exploring is always nice (especially if it's something like a maze that's sensitive to that), and in general have an idea of what you're doing.

The problem I see some DMs make is that they have everything planned out, and they know just how everything is going to go... and then a player does something completely different, and then either all his planning becomes wasted time, or the forces of the universe compel the character to follow the pre-existing story (AKA Railroading).
Think about this: there's one of you, and N of them. You're likely looking at it as a whole, whereas they're looking at it in a sequence. They'll likely think of ideas you never even considered, and so you will have to improvise.
Improvisation is the most important skill a DM can have; even more important than story telling.

If you want to plan more rather than less, you could set up random encounter tables of all the creatures that live in the area (level appropriate of course). You could draft up character sheets for NPCs. Write up a few scripts for the more important descriptions in your campaign. There are all things I'll do some of the time, it really depends on how much time I have and how much I feel I should prepare that day.

[WeaselGuy]

Google don jon d&d... my wife uses it for random dungeons and stuff, and I think it has a loot generator too. Also, in my decade of playing 3.5, the best advice I can give would be to write down the AC and HP of pretty much everything and everybody the PCs are likely to encounter. Because, lets face it, most PCs are a bunch of rampaging murderhobos that will likely attack anything they think they can get away with, simply because "I'm CN, it's in character " So, if you have an unpopular mayor or somebody like that, and you're pretty sure the PCs might at least think about attacking him, have a few guards in the back room with manacles and blunted weapons. Voila, you now have a prison break scenario to write!

[PaucaTerrorem]

Plan for everything that is remotely possible for the PCs to do. Then throw it all away. PCs will always do the one thing you didn't think about.

[atemu1234]

Plan for everything that is remotely possible for the PCs to do. Then throw it all away. PCs will always do the one thing you didn't think about.

I remember something like that from the guy that taught me how to DM. Man, that brings back memories. I find, however, that if you can gauge your PCs well enough, you can figure out what they'd do in a situation. Granted, it seems a little like mind reading, but I've got it to work more than once.

[Mystia]

Much wisdom has already been said here, but to add up on a few things that I, personally, consider to be essential, I'd like to recommend a few websites for you to check out and play around with.
I've grown quite fond of using random generators for sorting out minor stuff that, while being essential, could (and, more than often, do) take too much time. Be it the name/motivations/description of minor NPCs, or a few details about that village the PCs decide to visit on a whim, those things may really come in handy.

Donjon has already been mentioned, and I quite recommend it, but also do search for "Chaotic Shiny", "Seventh Sanctum", "Fantasy Name Generators" and "Serendipity generator". I'm sure you can find a good use for those. Also, if you want to add a bit more color to the travels the party makes, you can look around for "Benign encounters", and drop one into your scene descriptions every now and then.
I'm kinda... perfectionist, so I don't like not having at least a few lines of description written for every city, fort, forest, marsh, kingdom or any sort of major feature that I set down on the map, so those sites were incredibly helpful for me and saved an incredible amount of time and thinking, especially with names.

One thing that took me a few hours of work to get done, but was definitely worth it, was to create files listing several names and NPC descriptions/motivations, so that whenever I need to name an NPC on the spot I don't risk repeating myself and creating some "Nurse Joy/Officer Jenny" situations
I, personally, like to DM with my laptop by my side, so I keep said lists in there, separated in folders for each genre/race and so. But, of course, you may use them however you want, should you choose to do something similar. Besides that, most things have already been said. Take things easy at first and don't stress yourself too much, I'm sure you'll get the hang of it in no time.

Edit: just formatting and fixing typos.

[Malaqai]

Thank you all for the great advice - I'm already feeling a bit more comfortable in the DM seat!

[Flickerdart]

Prepare a few names. Your PCs must never know that the farmer they are talking to isn't a named character, otherwise they'll think he's not important and move on.