Why don't players get extra xp for large encounters?

Question

Based on the table Encounter XP Multipliers from the Basic Rules' DM section, Page 57, when you're building encounters in 5E, you include an XP modifier depending on the number of creatures your PCs will be fighting: 1.5x for a pair, 2x for 3-6 and so on. However, the PCs only get the base XP as a reward.

This doesn't change the actual xp reward ... just your calculations of how difficult the encounter is.

Why is this? After acknowledging that battles vs multiple opponents are more difficult, why not reward them as such?

Answer 1

A possible (and sufficient) motivation is to avoid encouraging players to game the difficulty system for greater experience gain.

A player aware of the XP system might be tempted to fight enemies in as large of a group as possible to ensure maximum XP gain. This would result in an over-difficult campaign and less fun for everyone, as the GM would have to do extra planning and the PCs would be consistently facing large groups.

A good way to eliminate this (and to encourage players to value high-level strategy as much as their PCs) is to only take encounter size into account when judging difficulty, not when judging encounter rewards.

This way you can have a kobold warren full of 20 kobolds in various chambers and not worry about the players deciding to kite the whole tribe into one encounter to maximize their XP. The players' desire for ease is no longer in conflict with their desire for advancement.

Answer 2

PC's get XP based on the monsters they defeat. Not based on how challenging the encounter is.

Basically, this functions as a throttle on leveling. You can fight more challenging encounters without leveling up as fast as you otherwise might.

However, it's worth noting that this is probably in part because these guidelines are just rules of thumb and not hard and fast "these monsters are twice as hard because you're fighting 3 of them now". It's simply a way to model how a mob of monsters can be more difficult than a single one, even without changing the XP budget.

This is pretty much a function of the fact that the XP budget is being asked to play two different roles. It's supposed to set encounter difficulty and also encounter rewards.

You can think of this as two separate, but related pools. You have Encounter reward-XP, and Encounter difficulty-XP. While they will often be equal, difficulty-XP is used to determine the encounter and daily XP budget, whereas the reward-XP is used to determine the space between levels.

I will say that this could use a much broader rules explanation and we should probably wait until the DMG comes out to pass too much judgement here.

Answer 3

Basing the XP award on the number of monsters fought at once would create additional work for the DM in any case where the players are able to adjust the number of monsters in an encounter, as it would require the DM to calculate the difficulty-adjusted XP value twice, once when designing the encounter(s) as intended and a second time to determine the actual XP award based on how the encounter(s) actually played out.

This applies both to cases of the players combining multiple encounters into a single fight when they feel able to handle the additional difficulty and to players who draw off smaller groups of enemies from a larger encounter to reduce the difficulty. Either way, fighting the enemies in differently-sized groups than intended would force a recalculation of difficulty-adjusted XP.

Combats in which the enemy receives mid-fight reinforcements would also become tricky (if not nightmarish) to calculate XP for: Do you use the multiplier based on the total number of monsters faced over the entire course of the fight? Do you go by the maximum number of monsters on the field at any one time? Do you track the number of monsters active in each round of combat, then average that out over the fight and base the multiplier on that number? When each monster dies, do you make a note of the number of monsters still standing and apply a separate difficulty multiplier to each monster based on that? Players who fight a group of enemies down to a single surviving opponent, then kite that survivor into the next encounter so that it becomes "just one fight" would introduce the same complications.

Awarding difficulty-adjusted XP would add way, way more complexity to determining XP awards than it's worth.

Additionally, many DMs (and published adventures) design things so that the PCs will be a certain level at certain places in the plot. Doing so requires knowing up front how many XP they're likely to receive before reaching that point. If XP rewards are difficulty-adjusted and players are free to take actions which might affect the difficulty adjustments, then it is no longer possible to design in this way because you can't know accurately how many XP the PCs are likely to have received.

Answer 4

This is a misreading of the rules.

Step 2: Add up Encounter XP

Total the XP values of every enemy creature in the encounter to get the encounter’s XP value.

This is the actual XP the players will get (divided up by the number in the party) based on defeating this encounter. If you fight 10 ogres, it's ogre XP times 10. However, this is not the final number used to calculate the difficulty of the encounter, which comes next.

Thus, if you have an encounter with 4 monsters in it, multiply the total XP value of the encounter by 2 for the purposes of determining how difficult the encounter is. This doesn’t change the actual XP award the adventurers receive for overcoming the monsters, just your calculations of how difficult the encounter is.

The bolded is important. It means that this step is solely about determining the difficulty on the Encounter Difficulty XP per Character chart, not the XP the players will get.

So let's say 20 monsters who are 10 XP each are attacking the party. Together, the party will split 200 XP for beating it. But how difficult is the encounter? It's as difficulty as an 800 XP encounter (200 xp multiplied by 4 for 15+ enemies), but you're only getting 200 from it.

What it does

First off, it accounts for certain things that come up with multiple monsters:

1. Economy of actions - more monsters grants more actions to the DM
2. Map space - a lot of monsters allows the DM to control the movement on the board better
3. Support multiplier - monsters who can buff or heal each other can get significant advantages in large numbers
4. Increase number of attacks = increased odds of critical hits

So taking that idea of 20 monsters of 10 XP, they'd be a "medium challenge" for 4 PCs if you didn't take into account that multiplier - but with the multiplier, it is easily double the number for "Deadly". It helps the GM not overwhelm the party given the factors I listed.

At the same time it acknowledges the difficulty of mass numbers, it doesn't give further REWARD for mass number combats. You may still want to take out those 20 monsters - it's just going to be more to your benefit as players to take them apart in smaller units a bit at a time, rather than trying to rush them in one battle.

Summary

1. Add up all the monsters' XP. This is how much the party will get if they defeat the encounter.

2. Multiply that total by the Encounter XP Multipliers SOLELY FOR THE PURPOSE of checking how difficult the encounter will be compared to the party.

Answer 5

I'm guessing the idea is to reward/encourage clever play by making one big fight vs 20 kobolds give the same xp as several smaller & easier fights if the players can split them up or take them out separately.

Not sure it works as incentive for that tho - since half the players wont know/care and the rest would be doing the clever (actual clever may vary by party/player) plan anyway.