Wizards go 'boom' (or 'woosh')
Certain classes are really good at ending an encounter in a single move, especially at lower levels. The most obvious problem is the Fireball spell, which will end almost any encounter with Goblins and the like before it has truly even started, blowing every enemy to kingdom come.
Normally, this isn't that big a deal, because ...
It doesn't actually "break" anything
Although it definitely affect the game in a few ways, which you or your players might find interesting or unsatisfactory, depends on your preferences. 5e doesn't have the one "correct" way of playing, it gives you options instead. The Dungeon Master's Guide has even less constrictive initiative variant, so the game is ...
A surprised monster who rolls a 20+ on initiative can use lair actions because they are able to take actions, and their turn has passed
As you've quoted, the rules on lair actions state:
On initiative count 20 (losing all initiative ties), it can use one of its lair action options. It can’t do so while incapacitated or otherwise unable to take actions. ...
Roll Initiative long before the attack
Yes, initiative could have been tracking time and movement and actions before combat—you just have to make clear to the players that you are using it for tracking purposes and that combat is still its own thing. Call it « stealth time » if you want—it works the same way.
Ever snuck around in a video game?...
If I were asked to DM this situation, I would probably go with the non-RAW solution.
I would split the participants into 4 groups:
The orcs by the fire
The orcs in the tents
Any non-surprised orcs (e.g. who have feats or pass a passive/active Perception check)
In this case, I would allow the orcs at least a passive check, due to the wizard ...
This is not ambiguous, neither does it depend on the DM. By RAW, the following happens:
Before even rolling for initiative, check if the wizard was stealthy enough to not be noticed by the orcs (we assume he did). We also assume the party is cooperative and they know the wizard's plans and the relative timing for the wizard to act. Everyone in the map rolls,...
It's complicated and some of it is up to the DM
Let's start with the Surprise rules:
The DM determines who might be surprised. If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing ...
The orcs are surprised.
Everyone rolls initiative. Everyone acts as normal on their turn.
PCs who act before the wizard can use their action to Ready something in response to the wizard becoming visible. This limits their options, for example they miss out on Extra Attack and their Bonus Action by acting on the wizard’s turn but that’s the ...
A non-RAW house rule that works far better
I'm going to give an answer based not off the rules, but off my experience. I've started handling this kind of situation differently in the last year or so and it's made play much easier (and more fun) without any real downsides. Here's my system for handling surprise rounds:
Roll initiative as normal. Roll ...
Let's dissect this piece by piece
First you mentioned that the orcs do not notice them. This means when the Wizard attacks, the orcs are surprised when combat starts.
Next the Wizard, still out of combat casts Invisibility which has a verbal component and may alert the orcs. If they still don't then continue but if they do then it becomes a normal case of "...
This sounds like a textbook case of surprise.
Determine surprise. The GM determines whether anyone involved in the combat encounter is surprised.
Establish positions. The DM decides where all the characters and monsters are located. Given the adventurers' marching order or their stated positions in the room or other location, the DM ...
Just don't ever participate in combat
Per the Initiative rule:
When combat starts, every participant makes a Dexterity check to determine their place in the initiative order.
So, you only make Dexterity checks for initiative when you participate in a combat. What exactly it means to "participate" isn't particularly well-defined (and has led to many ...