Creating balanced combat encounters can be surprisingly difficult,especially for newer Dungeon/Game Masters (DMs / GMs). If using the 2014version’s Dungeon Master’s Guide (DMG) you need to consult severalinterrelated tables for each encounter. Even though the 2024 version offifth edition D&D streamlined this process slightly it can still becumbersome to balance an encounter. To help other newbies,dndR includes a handful of functions aimed at simplifyingthe encounter balancing process.
If you’d rather avoid consulting the rulebooks at all, theencounter_creator function may be a valuable tool for youto consider. This function requires the average level of all playercharacters in the party (if all players are the same level this is justthat level), the number of players in the party, which version of fifthedition D&D you’re using, and how difficult you’d like to make theencounter (allowable answers differ between the 2014 and 2024 versions).Once you’ve provided this information, it will automatically select onetougher creature and as many other creatures as possiblewithoutmaking the encounter more difficult than you specified.
There is also an optional argument to specify the maximum number ofcreatures if desired. The 2024 version is particularly susceptible toincluding a number of monsters that–while mathematically appropriate–canbe logistically challenging to actually keep track of during a sessionbut this argument may also be helpful for those playing under the 2014rules.
The function returns a dataframe with one row for each uniqueexperience point (XP) value of the selected creatures. A separate columnindicates the number of creatures worth that amount of XP that should beselected in the encounter. The function also returns the “pool” of XPavailable for the encounter and the realized XP “cost” of the chosencreatures. More detail is provided on this later in this vignette butfor now keep in mind that there is an optimization step being done underthe hood so this functionmay not always return identicalresults. I suggest running the function more than once until you aresatisfied with the results! Or increasing the “try” argument to give thefunction more chances to find the optimal encounter composition.
# Pick a hard set of creatures for a four-person party of 3rd level characters## Try 10 times to find the 'best' encounterdndR::encounter_creator(party_level =3,party_size =4,ver ="2014",difficulty ="hard",try =10)#> # A tibble: 4 × 4#> creature_xp creature_count encounter_xp_pool encounter_xp_cost#> <dbl> <int> <dbl> <dbl>#> 1 200 1 900 890#> 2 100 2 900 890#> 3 25 1 900 890#> 4 10 2 900 890# Design a moderately difficult encounter for a 3-person, 8th level party with no more than 6 creaturesdndR::encounter_creator(party_level =8,party_size =4,ver ="2024",difficulty ="moderate",max_creatures =6)#> # A tibble: 5 × 4#> creature_xp creature_count encounter_xp_pool encounter_xp_cost#> <dbl> <int> <dbl> <dbl>#> 1 5900 1 6800 6795#> 2 700 1 6800 6795#> 3 100 1 6800 6795#> 4 50 1 6800 6795#> 5 25 1 6800 6795After this function has identified the number and XP value of thecreatures in this encounter, you may consider using otherdndR functions to identify specific creatures (e.g.,creature_list, etc.) or use your favorite source book /homebrew to decide on particular creatures.
This may be more detail than you require but a small description ofhow experience points are used to balance encounters (in and outside ofthis R package) will be useful context for some of the other encounterbalancing tools described below. In the In essence, the difficulty of acombat encounter in Dungeons and Dragons is affected by four things:
The first three go into the “pool” of available experience points tospend on a given encounter regardless of whether you’re using the 2014or 2024 version of fifth edition Dungeons & Dragons. If you’re usingthe 2014 version, the number of enemies is used to calculate a realizedXP cost by applying a multiplier to the XP pool. In the 2024 version,the XP pool is the XP cost but there is a qualitative note in thePlayer’s Handbook that GMs will want to be careful about the number ofenemies.
Because it’s simpler, let’s start by identifying the XP pool for agiven party under the 2024 rules. Let’s imagine that we have a 3rd levelparty composed of four players and we want to know how much XP is neededto make a moderately difficult encounter. We can use thexp_pool function to do this! Note that the names of thedifficulty levels also differ between the 5e D&D versions.
# Calculate pool of available XPdndR::xp_pool(party_level =3,party_size =4,ver ="2024",difficulty ="moderate")#> [1] 900If you’re playing under the 2024 version, simply take this number,open up your favorite website or source book and identify creatureswhose XP can be added up to be equal to or beneath that value!
The 2014 DMG handles the total XP pool and the XP cost in twoseparate tables. In order to balance an encounter you need to carefullyconsult both of them. Often this involves iterative testing of whichnumber and combination of creatures is below the available pool afterapplying the relevant multiplier.dndR provides twofunctions to handle this instead:xp_pool andxp_cost.
Let’s begin by calculating the XP pool from the same party as abovebut under the 2014 rules version.
# Calculate pool of available XPdndR::xp_pool(party_level =3,party_size =4,ver ="2014",difficulty ="medium")#> [1] 600Once you have that in mind, you can make a note of that number andthen usexp_cost repeatedly until you find the highestrealized XP cost that will still fall beneath that threshold. Note thatusingxp_cost while specifying the 2024 rules (i.e.,ver = "2024") will return a warning because the XP poolreturned byxp_poolis the XP cost in that versionof fifth edition D&D. Interestingly, the level of the party has noeffect on the realized XP cost; only the number of players and number ofenemies matters!
# Identify 'realized' XP of two monsters worth a total of 800 XP versus our partydndR::xp_cost(monster_xp =500,monster_count =2,party_size =4,ver ="2014")#> [1] 750Even though the total XP value of the creatures is beneath thethreshold identified byxp_pool, the realized XP cost ishigher after the appropriate multipliers are applied. Usingxp_pool alone would risk creating a much harder encounterthan you intended. In fact, in this case, that realized XP value isactually appropriate for a “deadly” encounter! Because player characterstend to be stronger under the 2024 rules (all else being equal) this XPcost versus pool comparison is no longer necessary.
Whileencounter_creator is meant to avoid needing to usethese helper functions, you can of course use these if you’d rather takea middle path between relying entirely on this package versus relyingentirely on the core rulebooks.