D&D 5E 11th Lvl Wizard and Cleric OK to Take On Two Banshees?

[tomBitonti]

Adding the second banshee considerably worsens the players chances.

If saves are 10% likely to be successful, the chances of two failures go from 1% to 3.6% if the number of banshees is increased from one to two.

This issue of stacking saves is a problem of encounter design: There are big, non-linear increases in the chance of total failures. That is to say, adding a dozen more bugbears has a very different effect than adding a dozen harpies. Attacks add linearly to damage. Pass-fail saves add non-linearly.

The lesson that I've learned is to avoid stacking save effects. Change the encounter from two banshees to one banshee plus another creature.

Net:
Result | 1B | 2B
1F1P | 0.18 | 0.3078
2F | 0.01 | 0.0361
2P | 0.81 | 0.6561

One save, two characters, 10% failure chance

FF 0.01

FP 0.09
PF 0.09

PP 0.81

1F1P = 0.18
2F = 0.01
2P = 0.81

Two saves, two characters, 10% failure chance

PPFF 0.0081
PFFX 0.009
FPXF 0.009
FFXX 0.01

PPPF 0.0729
PPFP 0.0729
FPXP 0.081
PFPX 0.081

PPPP 0.6561

1F1P = 0.3078
2F = 0.0361
2P = 0.6561

TomB

 

[FrogReaver]

I disagree in the strongest possible sense; on many levels. First off, encounter design and placement is NOT "mere contrivance", at least not in any game I run or create.

Encounters are designed to be:

• Evocative (of the theme and plot elements I'm trying to communicate to the players)
• Reasonable for the setting and presumptions of the game world
• Challenging and ultimately rewarding or "fun" for the PLAYERS (i.e. not necessarily their characters) to fight.

Okay, but I was talking about encounter difficulty and regardless of those other things, the difficulty is contrived to be at a level that is challenging and rewarding or fun for players.

Gamist? Absolutely, but not ENTIRELY gamist. Also note that the lattermost isn't actually dependent on "encounter strength". I could easily create fights that the PCs will win 100% of the time without any casualties - but are interminably long. Alternately I could create reasonably but not overwhelmingly dangerous encounters that would be finished in far less time than it takes to set up combat placement and turn order in the first place.

Neither of which fall in the category of challenging and rewarding or fun. I’m not really sure what such encounters have to do with anything.

Over the longer term, if there is no actual risk or perception of risk in encounters the entire combat experience devolves into a grind. Individual player choices cease to matter because the party will win regardless of what they do. That isn't entertaining for me or anyone else I know personally. For this reason, it is critical to at least occasionally include encounters that are potentially lethal.

Agreed. No problem with lethal encounters.

Except that it isn't. The PCs made the personal, tactical decision to split up. Changing the encounter midway through the session or adventure is one of the cardinal DM sins - circumventing the consequences of player choice.

But when the encounter difficulty was initially designed with the whole party in mind without player input, then there was no player choice in the encounter difficulty to begin with.

If one was to run a game with encounters completely independent of party strength I think the not changing encounters to match party strength when split makes sense, but if you are already contriving encounters to roughly match party strength, then failing to do so when the party splits seems way off IMO.

 

[MarkB]

Well to start with, you aren’t going to twice as many places.

Per unit of time, you are.

 

[FrogReaver]

Per unit of time, you are.

Yes, per unit of in-fiction time is the key, but never in total.

So why does the per unit of in-fiction time perspective matter over the total perspective? I’d say it doesn’t but I’m open to hear you explain that.

(And in real world time it’s probably the same pace whether split or not).

 

[pontinyc]

Adding the second banshee considerably worsens the players chances.

If saves are 10% likely to be successful, the chances of two failures go from 1% to 3.6% if the number of banshees is increased from one to two.

This issue of stacking saves is a problem of encounter design: There are big, non-linear increases in the chance of total failures. That is to say, adding a dozen more bugbears has a very different effect than adding a dozen harpies. Attacks add linearly to damage. Pass-fail saves add non-linearly.

The lesson that I've learned is to avoid stacking save effects. Change the encounter from two banshees to one banshee plus another creature.

Net:
Result | 1B | 2B
1F1P | 0.18 | 0.3078
2F | 0.01 | 0.0361
2P | 0.81 | 0.6561

One save, two characters, 10% failure chance

FF 0.01

FP 0.09
PF 0.09

PP 0.81

1F1P = 0.18
2F = 0.01
2P = 0.81

Two saves, two characters, 10% failure chance

PPFF 0.0081
PFFX 0.009
FPXF 0.009
FFXX 0.01

PPPF 0.0729
PPFP 0.0729
FPXP 0.081
PFPX 0.081

PPPP 0.6561

1F1P = 0.3078
2F = 0.0361
2P = 0.6561

TomB

Extremely helpful, thanks so much!

 

[deadman1204]

if you are sure they will win, add a 3rd so that you become uncertain.
When fights are always designed to be won, there is no real challenge. You realize the entire game is on training wheels and becomes a story of how you win, not if you win.

 

[ECMO3]

Just like the title says, the party split up and now they're looking at a 2v2 fight against a couple of Banshees (CR5). All the numbers say that they should be ok but I'm worried about them failing their saves on the Banshee's wail, thus dropping them immediately to 0 hp.

Yes, they were rash in splitting up but the player's are having a blast so I'd really love not to kill them because of a save or suck ability, but the banshees are both close relatives of theirs that they must kill in order to free their souls.

Thoughts?

Thanks in advance for any help!

Most of the time the Banshees will be slaughtered. This fight is "Trivial" in a game where "Deadly" is usually not Deadly.

 

[Paul Farquhar]

With only two PCs, it makes the game very swingy against anything. these are quite high level spellcasters, and therefore well equipped to deal with whatever, provided they aren't taken by surprise, but generally, with only two players I would use sidekicks or secondary PCs to bump the party up to four.

NB, the CR calculations assume 4 PCs for action economy. Not that it's terribly reliable in any case!

As already mentioned, in this particular situation, the most likely outcome is the banshees die like punks, with a slim but non-negligible chance of a TPK in round one instead.

 

[TiQuinn]

So how did it end up going for the two PCs?

 

[pontinyc]

So how did it end up going for the two PCs?

Thanks for asking, TiQuinn. Went great. The cleric dropped to 0 but the wizard was able to get him back up and they barely beat the banshees due to some bad rolls. Was exciting and odd and fun as hell.

Many thanks to all for all of the fantastic input!