D&D General BBEGs shouldn't miss.

[Charlaquin]

I’m dating that if a dm accidentally creates a cr+10 encounter I hope he fudges and makes the adventure fun and exciting instead of just declaring he made a mistake and come back next week when he gets it right.

Oh! Ok, gotcha. To me, that’s the kind of mistake that either comes from inexperience or over ambitious experimentation, both of which are things I’ll gladly forgive. Whether they deal with that by fudging the results or by calling for a mulligan on the whole encounter I’m not particularly bothered by either option, so long as they own the mistake and learn from it.

 

[Stalker0]

I basically give BBEGs a big bonus to their initiative or just lock it in at a high level. Learned the hard way that the dice don’t ensure an exciting final showdown.

This I agree with. Having the BBEG go last in the round is almost guaranteed to make for an boring knockdown. That said, legendary actions do make up for that somewhat as you still act after the first few people go.

 

[prabe]

I basically give BBEGs a big bonus to their initiative or just lock it in at a high level. Learned the hard way that the dice don’t ensure an exciting final showdown.

Part of the problem in my campaigns is that the players have put some build-effort into having their characters go early, so A) there's only so much I can do and B) I really don't want to negate their intentions, there. I mean, there are times when I could give the BBEG an extra +10 on init and between the character builds and my dice luck they'd still go last.

 

[Helldritch]

I’m dating that if a dm accidentally creates a cr+10 encounter I hope he fudges and makes the adventure fun and exciting instead of just declaring he made a mistake and come back next week when he gets it right.

Not even then I will not fudge. But who says the cr 10+ encounter must see the players? The players normally have scouts.

Encounter roll. Five Fire Giants, the group is only level 6...
What I would do.
You hear thunderous shouts and rumble ahead.
the ranger/rogue/sneaky character: "I sneak to see what's going on."
DM: Ok. Roll sneak with advantage
The player (Quite happy): Ok, 2 and 14. That makes a 22!
DM: You see Five fire giants playing catch the ball with boulders. One of them is clearly the referee. They do not notice you as they are too concentrated on their games to catch on your presence.
The player: "Ok, I sneak away, warn the group and we give them a wide wide berth"

This was clearly an encounter to avoid. Encounters like these make the world alive and feel dangerous. You could replace the fire giants with an ancient red dragon eating something big or whatever. There is nothing that can be avoided and giving advantage to a roll almost ensure that the player will succeed. If not, then a highway robbery of the players might be in order. (there is a reason I give inspirations rolls... reroll man, reroll.)

 

[Don Durito]

To me the decisions seem fairly obvious.

Is your BBEG, a villainous counterpart to the heroes?

OR

A monster.

If the former, you want to at least preserve the feeling that there are certain rules in place. PCs only get to act once a round, so exactly why should the evil wizard get to break the rules and take two actions in a round and cast two spells etc? If you want to make this fight challening it really can't be a solo fight. If not minions and bodyguards then give them resources that can make it not a solo fight - such as for example have them carry an elemental gem that can summon an elemental to fight alongside them. (Some version of animated objects would be another option). I'm not arguing that villains should follow the exact same mechanics as the PCs - only that it should feel like they more or less do.

If the latter you can of course break the rules. That's what legendary actions are for. I would also think about how this can be themed. For example the boss orge could have two heads. This nicely explains why it's extra tough (twice the hitpoints) and has initiative actions in a round (two heads are better...)

 

[Don Durito]

Not even then I will not fudge. But who says the cr 10+ encounter must see the players? The players normally have scouts.

Encounter roll. Five Fire Giants, the group is only level 6...
What I would do.
You hear thunderous shouts and rumble ahead.
the ranger/rogue/sneaky character: "I sneak to see what's going on."
DM: Ok. Roll sneak with advantage
The player (Quite happy): Ok, 2 and 14. That makes a 22!
DM: You see Five fire giants playing catch the ball with boulders. One of them is clearly the referee. They do not notice you as they are too concentrated on their games to catch on your presence.
The player: "Ok, I sneak away, warn the group and we give them a wide wide berth"

This was clearly an encounter to avoid. Encounters like these make the world alive and feel dangerous. You could replace the fire giants with an ancient red dragon eating something big or whatever. There is nothing that can be avoided and giving advantage to a roll almost ensure that the player will succeed. If not, then a highway robbery of the players might be in order. (there is a reason I give inspirations rolls... reroll man, reroll.)

I think the example was meant to be accidental. Like for example you meant the bandits to be a not particularly dangerous threat for a 3rd level party and you intimated as much but decided they needed a spellcaster and you for some reason threw in a Rakhshasa at the last minute without checking how dangerous they actually are.

Although I'm not sure I see how this could actually happen.

 

[Helldritch]

Part of the problem in my campaigns is that the players have put some build-effort into having their characters go early, so A) there's only so much I can do and B) I really don't want to negate their intentions, there. I mean, there are times when I could give the BBEG an extra +10 on init and between the character builds and my dice luck they'd still go last.

1) Have the BBEG be proactive against the player. Do not let them choose when they meet it whenever it is logical to do so.
2) Make sure that the players have a few encounters before meeting the BBEG. With fewer resources it will be harder on them.
3) If they insist on resting before the big showdown. Let them rest. Depending on the BBEG, it might be a death sentence for them. Especially if they use Tiny hut. Have the BBEG have a caster and dispel that hut. Bang the BBEG will fight on its terms. If not, have the BBEG have reinforcement (one of my favourite). Make it clear that the longer they take, the more reinforcement the BBEG will get.

Also, BBEG are build for 4 players in mind. Having more means that BBEG are not at their best. I have two groups of 6 players. My BBEG are modified to respect that.

I use this:
Single encounter big bad guys
Add 1 feat/ASI per 4 CR (save the first four)
Add 1 legendary action per PC above 4.
Multiply HP by 1 +0.25 per PC above 4.
Add 1.5 AC (round up) per PC above 4.

Here is a modified lich my players defeated at 17th level in a previous campaing.

AC: 17 (natural armor + dex) Now 23 (+1.5 AC x 2 for players number, Staff of power and +1 ring. It could go up to 25 for one attack because of the shield guardian and I am not counting shield. Since shield was an at will power, it became and AC 28 and 30 for one attack)
HP: 135 (18d8 + 54) Now 238 for a 1.5 multiplyer for number of players and tough feat (+36hp).
Spd: 30' (unchanged)
Stats: Unchanged (decided to use feats instead...)
Added: Warcaster, Elemental Adept Fire (that one was a surprise for my players), Tough.
Mage feature added: Shield and Mirror image at will (I counted that one as a feat)
Spell list was changed to reflect the added mage feature and feats.
Cantrip: Removed prestigiditation and added Fire Bolt. Rose number of cantrip to four and added Green Flame blade
Level 1: Removed shield and added disguise self (Lich used it to appear human as she did in her life.)
Level 2: Removed Mirror image and added Misty step instead.

Legendary action Rose to 5 (again 6 players)

Lich was also using Staff Of Power And a Shield Guardian.

It does not make BBEG overboard. But it does make them harder for larger group.

 

[Helldritch]

I think the example was meant to be accidental. Like for example you meant the bandits to be a not particularly dangerous threat for a 3rd level party and you intimated as much but decided they needed a spellcaster and you for some reason threw in a Rakhshasa at the last minute.

Although I'm not sure I see how this could actually happen.

Me neither... A rakshasa with bandit... Ouch.

One other way to avoid this is to roll encounters way in advance before the session for overland travel. It is during overland travel that a lot of the "Killer Random Encounters" happen. You generally know how long and where your players will travel. It makes for better random encounters (as you can adapt them far in advance) and can even spring new improvised adventures on the run. Where are those ogres coming from? Time to build a nice grotto or something...

 

[prabe]

I think the example was meant to be accidental. Like for example you meant the bandits to be a not particularly dangerous threat for a 3rd level party and you intimated as much but decided they needed a spellcaster and you for some reason threw in a Rakhshasa at the last minute without checking how dangerous they actually are.

Although I'm not sure I see how this could actually happen.

I overcooked an encounter when I tried to homebrew something based on a third-party product, after (I thought) I'd gotten a sense for CR in 5E but before I'd read about how third-party stuff is often nastier. It was entirely my own fault, and I apologized for it. Relatively little harm done.

 

[Charlaquin]

I think the example was meant to be accidental. Like for example you meant the bandits to be a not particularly dangerous threat for a 3rd level party and you intimated as much but decided they needed a spellcaster and you for some reason threw in a Rakhshasa at the last minute without checking how dangerous they actually are.

Although I'm not sure I see how this could actually happen.

Like I said, inexperience or over-ambition. Either a new DM who just wanted to use a cool-sounding monster and didn’t realize it was way stronger than they thought it would be, or a DM who tried to homebrew something and accidentally made it way harder than they meant to - which could itself either have been the result of being new to home brewing monsters and not having a good feel for it yet, or of trying something really wild that even with your experience you couldn’t accurately predict.

EDIT: Or as @prabe points out, a DM who mis-evaluated third party material, which could come either from inexperience with evaluating and vetting third party material, or from said third party material being so out there the experienced DM didn’t know how to evaluate it but wanted to try it anyway.