Initiative: 10

Muirgurn's initiative: 8

Initiative: 21 

Razil, you see Peter and Aldrich taking aim at the giant rats with their bows while Muirgurn's incantation signals that he's about to cast a spell. Meanwhile, you can see the rats starting to move in towards you and your companions, their fighting instincts having been awakened by the intrusion, but before they move you have a chance to act. What do you do?

(I'm thinking that Muirgurn and Aldrich are in the front row of the group, with Peter and Razil in the back.)

(Also, remember that the entire room is difficult terrain because of the rubble, so movement speeds are halved.)

Focusing on the beast in the middle of the pack (R4), Raz's tail swishes slightly as he bristles with energy.  Pointing his rod, he unleashes an Eldritch Blast at the creature.

Attack: 23 Damage: 3 

The rat's hair stands on end as it absorbs the energy beam, leaving it chastened in its resolve.

Aldrich lets fly an arrow at the next closest rat (R3). Attack: 20 Damage: 7

Aldrich's arrow strikes true, and the great rat dies instantly.

The one that was hit by Razil's energy beam (R4) turns tail and runs to the back of the room, squeaking as it disappears from view behind the mounds of debris, and the one on the far left (R1), seeing it run past, follows its lead, ducking behind the rubbish piles as well. Both of them try to hide. Dexterity: R4 21, R1 6 

The other two rats (R2 and R5) move in cautiously with fangs bared and take low defensive postures, watching your every move (the Dodge action).

R1 is doing a terrible job of hiding, knocking over a stack of stone blocks and raising a small dust cloud to mark its location, but R4 has evaded the notice of Razil and Aldrich.

Peter, Muirgurn, and Razil, you're up.

Muirgurn unleashes sacred flame upon the rat known as 'R5' (Dex DC13 or 3 radiant).

Peter, I assume you let loose your arrow. Name your target. 

((I do, I was just waiting to see if someone got in melee with one lol, I'll attack R5 too)

Peter pulls back his string and scans for the best shot, deciding to send an arrow flying after the light of Muirgurn's sacred flame

25 to hit doing 6 piercing damage

((Idk if we just double dice rolled or roll a second die for crits, but if so 2 additional crit damage))

Razil turns his attention to the next closest rat (R2, assuming R5 has died), and uttering his arcane chant again fires off another Eldritch Blast

Attack: 14 Damage: 8 

Rat 5, seeing radiant flames descending around it, attempts to avoid them. Dex save: 11

Peter and Razil, attacks against R2 and R5 have disadvantage because they took the Dodge action, so make a second attack roll to confirm your hits.

The rat (R5) is burned and singed by the radiance, but still stands its ground on the mounds of rubble.

Disadvantage Attack Roll: 19 

disadvantage roll: 18 to hit

Peter's expertly aimed shot slays the singed rat (R5), and it falls dead.

Razil's energy beam zaps the other approaching rat (R2), and a small cloud of smoke rises from its back.

Aldrich takes aim at it with his longbow. Attack: 10 Damage: 5

The rat ducks out of the way of Aldrich's arrow, which narrowly misses, and it continues to scramble over the rubble towards you, ready to dodge the next barrage of attacks.

The other two rats stay in their hiding places and also focus on dodging any attacks that come their way.  R1's location is obvious to all, while R4's is unknown to Razil and Aldrich.

Peter, Muirgurn, and Razil, you're up again.

(All rats are "dodging" now, so attacks against them are at disadvantage.)

Raz will fire off another Eldritch Blast at the closest living rat when it's his turn.

Attack: 14 Damage: 10 

Peter brings his bow up to aim at R1, releasing an arrow ((11 to hit doing 4 piercing))

Sorry Peter, I should have stated more clearly that R1 and R4 have total cover from the four-foot tall pile of rubble they're behind, so they can't be targeted directly. I realize what I said about attacks against them having disadvantage confused the issue. I think I was a little confused myself. :)

That being said, you can switch your target to R2 if you want.