Quick DMing Queston

[AKShadow22]

So I'm still newish to DnD and I'm going to be running a 3.5 Campaign and I just wanted to run something by the forum. The final battle of the campaign can be one of two things happening with this being what happens if they end up joining the BBEG, which is a possibility. So in this fight there should be 5 lvl 20 PC in the party and my question is would it Be fair to throw a lvl 20 knight and a lvl 20 Cleric at them? Just for reference the BBEG is a Very old Gargantuan Purple Dragon.

[Honest Tiefling]

This isn't a quick question. The environment, preparedness of the enemy, tactics, builds and equipment all play a factor. Usually CR 20 means that the creature is made for a group of four, but you got one extra, and we have no idea what their power level is. Perhaps replace that Knight with minions?

[AKShadow22]

This isn't a quick question. The environment, preparedness of the enemy, tactics, builds and equipment all play a factor. Usually CR 20 means that the creature is made for a group of four, but you got one extra, and we have no idea what their power level is. Perhaps replace that Knight with minions?

Yeah you're right it isn't a quick question, so sorry about that. Just wanted to hear other opinions on it.

[Esprit15]

The dragon is hard to pin down, just because there are so many ways to set up its spells and feats. It could wind up being a cakewalk if run or built poorly, or be nigh impossible if run well. Assuming semi-competent building (not high op, not wizards with weapon focus), the dragon should be more than sufficiently challenging, especially if they have time to plan (casting scintillating scales, mage armor, and other defensive buffs before the fight begins).

For the knight and cleric, it really, really depends. Are you doing things like Divine Metamagic: Persist with the cleric to make him out-Fighter the fighter? If so, then he might be more than enough, unless the party plays to that level of power. If they have a few competent players, the knight might be necessary, though I also echo the suggestion of a few lower level NPCs instead, acting more as distractions. If the party is getting bogged down by a few level 10 rogues (normally something of minimal threat in an up-front fight), the level 20 cleric is that much more terrifying.

[EyethatBinds]

5 20th characters should be able to win against a CR 22 to 23 fight given adequate prep time. If they know the villain, even a little at that level, they should have the ability to prepare for the specifics of the fight long before the battle starts.

I made a group of five 24th level characters square off against 4 20th (ECL) monsters and their great wyrm red dragon master at the same time. I guessed it to be roughly a CR 26 fight for XP rewards. At least, that's what the party would have gotten if they didn't all die in four rounds.

[nedz]

It depends upon the party, their builds, their build OP level and their general competence - but it should be OK.

[martixy]

Sure, it is.

You should learn what your PCs do well and what they don't.
That's a staple in DM best practices.

You can then build your BBEGs in such a way that you can dynamically adjust their apparent optimization level.
I.e. build them optimally and play them at whatever % of their potential results in a great battle.

[atemu1234]

The knight and cleric would technically be a EL 22 challenge when paired, but that only means that what a CR 20 creature is for a L20 party of four, that is what they would be for a L22 party.

I'd say they could probably handle it, if the cleric doesn't kill them.

[DarkSoul]

Considering you're talking about these two joining a dragon in the fight, I think you should keep one in reserve to see how the fight goes.

Create both of them, but when the fight starts, only have the knight with the dragon, and add the cleric if it looks like the party is going to have too easy a time. The reason I don't think you'll want both of them there at the start is because dragons are usually a bit overpowered for their CR and as was mentioned before, how they're created can swing their difficulty a lot.

[Esprit15]

Considering you're talking about these two joining a dragon in the fight, I think you should keep one in reserve to see how the fight goes.

Create both of them, but when the fight starts, only have the knight with the dragon, and add the cleric if it looks like the party is going to have too easy a time. The reason I don't think you'll want both of them there at the start is because dragons are usually a bit overpowered for their CR and as was mentioned before, how they're created can swing their difficulty a lot.

I read it as an either-or. If the party goes one way, they fight the dragon. The other way, they fight the cleric and knight.

[Chronikoce]

Are the players starting at level 20 or adventuring to level 20?

If they are adventuring to 20 then I wouldn't worry about it too much right now because you should gain a really good idea of what the party can handle as they progress.

If they are starting at level 20 then honestly my advice is, don't. Unless this is a one shot for fun, then go wild of course. Level 20 combat in 3.5 is entirely dependent on the optimization of the characters involved. You have one end of the spectrum where you get rocket tag (whoever goes first wins) and you have the other end of the spectrum where they will die to equal CR monsters (think party of un-optimized monk, fighter, samurai, and ninja).