Unearthed Arcana: Encounter Building Response

Introduction

Unearthed Arcana has a new article that covers guidelines for creating combat encounters. I've tried to create a table that maps level to challenge rating one to one (essentially translating level to challenge rating and vice versa) based on this article. Up until now we've mainly had experience and challenge rating to go on. Seeing this, I wanted to see what I could pull out and possibly organize into a new form as well as note anything else of interest I noticed.

Resulting Chart

The below chart uses the information in the multiple monster table provided in the Unearthed Arcana article. When two challenge ratings were given for a level, I took the highest. The result is a relative translation between level and challenge rating. If you like to use the player creation rules as a starting point for baddies, you might find this helpful.

Level	Challenge Rating
1	1/4
2	1/2
3	1/2
4	1
5	2
6	2
7	3
8	3
9	4
10	4
11	4
12	5
13	6
14	6
15	7
16	7
17	8
18	8
19	9
20	10

What We Get

It doesn't look like my resulting chart follows a pattern. It's probably best that if you just consult the charts and not memorize them. I'm happy to finally see the math behind challenge ratings and hopefully once it gets finalized it'll help a better level of consistency on Dungeon Masters Guild. The challenge rating for different group sizes was also a nice touch. I wish the table went to at least 3 players groups for solo monsters. You would think that you could use the tables to figure it out yourself, but it doesn't line up. The math for the multiple monsters table is different than the solo monsters table. Given the modifiers used in the Dungeon Master's Guide for larger groups of enemies (the difficulty of an encounter was the total experience points multiplied by a constant determined by the number of enemies), it's not too much of a surprise. Trying to work backwards by guessing would be a pain though and not guaranteed to yield a result. It makes me wonder if the table was made mostly through eyeballing things or whether there is some kind of hidden math. If it's hidden math, I'd like to see it.

The solo monster table is quite interesting to see. You would think that challenge rating should translate to something meaningful, like being a nice challenge for a party of 4 for that level. At fifth level, that pattern is quickly abandoned in the table. It reinforces that challenge ratings are odd. To make things worse, it specifically states that the table is for challenge a party by using a single legendary creature.

The table for dealing with multiple monsters in an encounter may be more useful. I'm hoping to see if I can successfully trim back an encounter to fewer characters by using it. Based on the text so far, it should use the same math as the other guidelines. However, the difference in the way it is presented means it will be easier to use for certain things.

I like the sections about monster personality and monster relationships. Too often I've seen the encounters where creatures are just buckets of hit points that need to be reduced to zero before advancing. It honestly seems to be stuff that should have been included in the Dungeon Master's Guide.

Is It Alternate?

Reading over these guidelines, it makes me wonder if it is indeed an alternate system or instead another system of checks we can use. If you know what creature you want to throw at your party or need a single legendary creature, it should make it easier to design the encounter. Using the second table, you can also choose monsters to challenge a single character and then multiply it by the number of characters, if you have a party of equal level. I think I might give that approach a try and see how it works. In the previous guidelines, however, the number of creatures used against the party influence the modifier. In the new method, the total number of creatures doesn't seem to be used. My concern at the moment is that these new guidelines will diverge from the old ones at times.  

Unearthed Arcana: Variant Rules Response

Every month or so, the Unearthed Arcana articles give early versions of potential rules for D&D 5^th edition. Up until now I haven't seen anything that would require my commenting. However, the article this month had a bunch of variant rules that I feel I need to comment on. Those of you using other systems than D&D 5^th edition will probably not find anything that you can use directly but some of the ideas may still be relevant. Beware: there be math here.

My Issues with Players Make All Rolls

The variant rules presented have a section detailing a method that allows players to make all of the rolls. I have no issue with this idea and in fact I have seen it used before. The main advantage this brings to the players is a sense of tension since they are rolling to hit as well as defend against attacks. However, when making rule changes we should always be careful of unintentionally messing with the probability of success.

First, let me do some math to work out the usual course of events for doing an attack. If we plot the distribution for a d20 we know the average is 10.5 with a maximum value of 20 and a minimum value of 1. We see that on average we are actually adding an extra 0.5 if we take armor class – 10 and then add the roll from our dice. This does not bother me though. Why? If we look at the other side of the attack we have the attacker's bonus + 11. That + 11 is meant to simulate the attacker rolling their dice and getting 10.5 on average. Since we skew both the attacker and defender by 0.5 we haven't really changed anything.

What's my problem then? Looking at the saving roll rules (now called a saving roll check) we see that we take our spell save DC – 8 and then add our roll from the d20. This means that we skew the player's change of success up by a 2.5 bonus or about 12.5%. However, the DM run character sets the DC for the check through their saving throw modifier + 11 (the roll still gives an average of 10.5). This skews the chance of success for the DM run character by 2.5% and means that the spell caster has gotten a 10% more chance of success. This can be fixed however by adding a +2 to the monster or a -2 to the player.

If you want to maintain the balance between spell casting classes and non-spell casting classes, this becomes a rather big issue. However, it gets worse. By the wording of the rules, a tie results in a success for the one rolling (this is how all checks and all other rolls against a DC work). Since the player now win ties, they gain an extra 5% chance of success for defense rolls against normal attacks as well as a 5% chance of successfully harming an enemy with their spell. To maintain the same chance of success we either need to explicitly say that the monster wins ties for defense rolls and saving throw checks or we will need to add an extra +1 to the monster in both cases.

How to Fix This?

1. Defense roll for a player is d20 + AC – 10 while the DC is attackers attack bonus + 11. Saving throw check for a player is d20 + spell save DC – 10. In the case of a tie, monster wins these two checks.
2. Defense roll for a player is d20 + AC – 11 while the DC is attackers attack bonus + 11. Saving throw check for a player is d20 + spell save DC – 11. In the case of a tie, the one rolling wins as usual.

There are others ways to fix it, but I feel the above two are the most elegant. To understand the problem, read the last two paragraphs of the above section. My personal favourite solution is the second one since we just need to remember 11 for everything.

My Issues with Vitality

I just don't see how this fixes the problem mentioned. A kobold can still finish off a high level injured fighter. It's an interesting way to add longer recuperation times based on the severity of the injury. However, to prevent this rule from favouring spell casters, we would need to treat all damage made from extra attacks as part of one attack. Doing so will mean that the higher level the players become, the more often they will see themselves lose vitality. In fact, at lower levels it is more likely the player will be outright dead than notice a loss of vitality.

I also feel that if the aim was to increase time to recuperate after sustaining injuries, doing so through an element already in the game such as the hit dice would be more efficient. Preventing instant healing from long rests and instead forcing hit dice use would seem like a better way to me. We can also play with the rate hit dice are regained until we are happy. In this case, there will be no outright death from lack of hit dice since players spend them.

Conclusion

While I generally didn't have an issue with the goals of the rules and the ideas presented, I had a few issues regarding the math and goal of the two variant rules I mentioned. There was also a section talking about alignment, but I had no issue with it. I also plan to talk about alignment in the future. As always, I hope this helps and feel free to point out any issues with my interpretations or my math.