Can you cast a spell before Initiative has been rolled? [duplicate]

Question

I've started Lost Mines of Phandelver a week ago and I want to know if I'm doing this right. My group has a rogue and a sorcerer in it.

When the rogue sneaks up on a target (he rolls a Stealth Check vs. Passive Perception) and succeeds I let him 'start combat' by attacking his surprised target and having everyone roll Initiative after to determine an order for combat.

Example:

• Rogue rolls a 16, Goblin's PP = 11, Rogue has surprised the Goblin
• Rogue attacks Goblin (1d4+2, 2d6 sneak attack) and Goblin dies.

Roll for Initiative!

• Rogue rolls 8
• Sorcerer rolls 12
• Cleric rolls a 9
• Other Goblins roll a 15

After the surprise round combat would go:

• Goblins
• Sorcerer
• Cleric
• Rogue

Does this work?

Also, is it different for this scenario:

Enter a room, Goblins are visible but distracted. Sorcerer says he wants to fireball them. Do I make him roll a stealth check vs. Passive perception? Or do I just have the Goblins make a dex save like they're supposed to, and then roll for Initiative afterwards?

The Sorcerer in my group has been doing this all campaign so far and I don't exactly have a good answer for why he can't do it.

Answer 1

On Attack, Initiative is Started Before the Attack Actually Occurs.

Rules As Written, when the rogue is about to make his attack, everybody rolls initiative.

Initiative Count: Goblins 15 Sorcerer 12 Cleric 9 Rogue 8

Any person unaware of the threat has the surprised condition. There is no "surprise round" in 5e, only characters being surprised -- it is like a condition, except the designers didn't take make it a formal condition.

Goblins, all unaware of the threat are surprised, and can't take action. The goblins are no longer surprised at the end of turn.

Now, party members likely Ready an Action until the Rogue goes, if they want. If they don't want, they can move and act (including attacking) on their turn. If sorcerer wants to fireball them here, they can, and it would be the dex save, arguably the DM could add disadvantage for being caught unaware.

On the rogues initiative count, he rolls his sneak attack. The conditions that make this sneak attack is the advantage gained from him still being hidden.

If any party member held their called action until the rogue attacks, there attack would happen here.

Back to the top, and it goes: Goblins, Sorcerer, Cleric, Rogue until combat ends.

Likewise, On Spell Casting

In the case of the opening action being the fireball -- when the player declares his intent, initiative is rolled. The goblins would again start with the surprised condition.

Perception and Stealth

As written, looking around to get a perception roll is an action. Hiding to get a stealth roll is also an action. If a character does stealth, unless someone is actively searching you compare the stealth roll from when the character hid, to the passive perception of nearby characters to know who, if anyone, sees the stealth-ing character. If a character is actively watching, spending their action watching, every round they are spending their action to roll perception check. Hiding also requires some form of cover -- you can't hide in a bright empty room (like you can in Skyrim :p ).

Variants

Pre-Rounds Attacks

Some DMs allow the first attack to happen outside initiative, this isn't rules as written, but is a fairly common house rule. The effect is typically one extra attack against one enemy, and if by a rogue basically means a bunch of free sneak attack damage. It's an alright house rule, and it is common, but it isn't the standard rules as they are written.

Contested Rolls When it "Makes Sense"

The rules also don't support extra contested stealth v. perception rolls, but some DMs might give them when certain factors change. Like, if a player moves "close enough" or takes certain actions while hidden.

Answer 2

The following is how I would run it with the specific rules I would follow.

Player's Handbook p189

Surprise

...

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 side. Any character or monster that doesn’t notice a threat is surprised at the start of the encounter. If you’re surprised, you can’t move or take an action on your first turn of the combat, and you can’t take a reaction until that turn ends. A member of a group can be surprised even if the other members aren’t.

Player's Handbook p177

Initiative

At the beginning of every combat, you roll initiative by making a Dexterity check. Initiative determines the order of creatures’ turns in combat, as described in chapter 9.

So looking at your example above:

Rogue rolls a 16, Goblin's PP = 11, Rogue has surprised the Goblin Rogue attacks Goblin (1d4+2, 2d6 sneak attack) and Goblin dies.

Roll for Initiative! Rogue rolls 8 Sorcerer rolls 12 Cleric rolls a 9 Other Goblins roll a 15

After the surprise round combat would go: Goblins Sorcerer Cleric Rogue

I would run it like this, assuming that the rest of the party are not a noticeable threat to the goblins (otherwise their Dexterity(Stealth) would have to be considered too). This means that the rest of the party are not in line of sight, nor within hearing of the goblins.

1. Rogue rolls Dexterity(Stealth) of 16 to sneak up on the goblins
2. DM compares roll with passive Wisdom(Perception) of goblins
3. None of the goblins notice a threat and thus are all unaware of a threat and none of the goblins can move or take an action in the first round of combat (wait for it, not yet)
4. Assuming that the rest of the party are aware of the threat of the goblins even though they are not in any way exposed to them, they are not surprised in the first round of combat and can move and act (wait for it, not yet)
5. The rogue's player declares an attack and combat starts so everybody rolls initiative (yes - everybody)
6. The goblins are surprised and they don't get to move or act in their turn on their initiative, but you still record their initiative. However it is important to note that once their turn has passed they do have a reaction, if one is triggered by the action of the rogue or any other event/skill/power.
7. The party members with initiatives higher than the rogue's move or act. However they are not aware of the rogue's action before they take it and so their actions, if before the rogue's, will probably be to Ready (Players Handbook p193) triggered by hearing or otherwise becoming aware of the combat starting
8. The rogue takes the round of action that includes the strike and maybe moves etc.
9. The Ready reactions from 7 are triggered
10. Any party members who have not acted yet act with a full round's actions in order of initiative
11. Next round, the goblins are not surprised and you follow initiative order

For party members to be able to act normally in the first round they have to take the risk of being a noticeable threat to the goblins. You can't have it both ways. Unless, of course, they have some sense that allows them to see what is happening such as Clairvoyance spell and a Wisdom(Perception) roll good enough to see the rogue where the goblins can't for instance.

Once you have done it a couple of times it makes sense and is actually quick.

Answer 3

The sorcerer needs to roll a stealth check vs. passive perception. PHB 189 describes this as the only way to attain surprise before an encounter. If the sorcerer fails his stealth check, everyone rolls initiative and the sorcerer casts the fireball on his turn as in normal combat.

It's important to note that everyone makes independent stealth checks, so that some characters might have surprise and others may not. Those who effectively have surprise have a turn of combat before all the others, and thus act in initiative order.

One imperfect way to imagine this is that the goblins are making a dex save to react faster than the sorcerer. Since casting Fireball is not instantaneous, if they notice the sorcerer casting the spell, they might try to scatter or fight back before the spell goes off. While some DMs (like me) houserule otherwise, I don't think there's RAW support for it.