Well I promised a new fight night. This time it is a group of goblins cleaning out a part of the dungeon for living quarters. What! They find giant centipedes in that room full of rubbish.
Here are the giant centipedes.
NO. APPEARING: 2-24 (3-13 in dungeon DMG p 177)
ARMOR CLASS: 9
HIT DICE: 1 to 2 hit points
NO. OF ATTACKS: 1
DAMAGE/ ATTACK: Nil
SPECIAL ATTACKS: Poison
SIZE: S (1' + long)
LEVEL/ X.P. VALUE: II/ 30 + 1/hp
- Weakly poisonous bite, add +4 to saving throw
- -1 on die for all saving throws
- Need a '15' to hit an AC 6 goblin
Now the goblins.
NO. APPEARING: 40-400 (6-15 in dungeon DMG p 175)
ARMOR CLASS: 6
HIT DICE: 1 to 7 hit points
NO. OF ATTACKS: 1
DAMAGE/ ATTACK: By weapon
INTELLIGENCE: Average (low)
ALIGNMENT: Lawful evil
SIZE: S (4' tall)
LEVEL/ X.P. VALUE: I/ 10 + 1/ hp
- Need a '11' to hit an AC 9 giant centipede
- They need a '12' to save vs poison against the bite of a giant centipede. It is normally 16, but I adjusted it by the +4 bonus.
Now it is time to roll up numbers and hit points. There are 3-13 giant centipedes (2d6+1). I roll 8. Their hit points are: 1, 1, 2, 2, 1, 1, 1, 2
There are 6-15 goblins (1d10+5). I roll 7. Their hit points are irrelevant, since hit points don't matter when fighting giant centipedes. They will either poison you or not.
Randomly rolling up weapons based on the monster manual entry reveals:
Goblin 1 has a short sword (1d6) and military pick (2-7)
Goblins 2 and 3 have slings (stones, 1-4, entire room is short range, so no adjustments)
Goblins 4 and 5 have morning stars (2-8)
Goblins 6 and 7 have spears (1-6)
As noted this is a dungeon encounter. Goblins are level I monsters and giant centipedes are level II monsters, so the goblins were probably feeling their oats and went down a level to clear out some dungeon for habitation.
Next is surprise. The giant centipedes roll a 5 and the goblins do, too, so no surprise.
Next is encounter distance. I will say the room is 20 'X 20'. Going by DMG page 62, the rule is to roll a d6. 1-2 will be striking distance, 3-4 will be 10' distance, and 5-6 will be 20' distance. I roll a 4, so the giant centipedes are 10' from the door.
We have to declare intentions. The giant centipedes “are aggressive and rush forth to bite their prey” so that is what they do. The goblins with slings attack from a distance, while the others move to engage. Time to roll for initiative. The giant centipedes roll a 6 and the goblins roll a 6, too, so it is simultaneous combat. Because the distance is 10', the two sides can have melee this round. Since the giant centipedes do not use weapons, weapon speed factor will not be an issue.
Random allocation of targets.
Centipede 1 attacks goblin 1, rolls a 15 and hits
Centipede 2 attacks goblin 4, rolls a 1
Centipede 3 attacks goblin 1, rolls a 5
Centipede 4 attacks goblin 3, rolls a 13
Centipede 5 attacks goblin 5, rolls a 4
Centipede 6 attacks goblin 1, rolls a 9
Centipede 7 attacks goblin 4, rolls a 3
Centipede 8 attacks goblin 4, rolls a 19 and hits
Goblin 1 attacks centipede 4, rolls a 3
Goblin 2 attacks centipede 7, rolls a 2
Goblin 3 attacks centipede 7, rolls a 19 and hits for 3 points of damage, killing it
Goblin 4 attacks centipede 8, rolls a 4
Goblin 5 attacks centipede 5, rolls a 11 and hits, killing it
Goblin 6 attacks centipede 3, rolls a 16 and hits and hits for 6 points of damage, killing it
Goblin 7 attacks centipede 2, rolls a 17 and hits for 6 points of damage, killing it
There is no need to roll for damage for goblin 5. He has a morning star which does 2-8 points of damage. Since giant centipedes can only ever have 2 hit points maximum, any strike will kill it.
Goblins 1 and 4 need to roll against poison, needing an '11' or better. Goblin 1 rolls a 5 and dies. Goblin 4 rolls a 13 and is okay.
Ok, end of round 1.
Goblin 1 is dead.
Centipedes 2, 3, 5, and 7 are dead. The centipedes are non-intelligent and don't follow normal morale rules, otherwise they would take a morale test now.
New round and new actions. The centipedes bite. Sucks to be a goblin whose only weapon is a sling. Goblin 2 picks up Goblin 1's short sword. Goblin 3 picks up Goblin 1's military pick. The other goblins melee.
Roll for initiative. The centipedes roll a 4 and the goblins roll a 2.
Centipede 1 attacks goblin 3, rolls a 11
Centipede 4 attacks goblin 6, rolls a 20 and hits
Centipede 6 attacks goblin 6, rolls a 10
Centipede 8 attacks goblin 6, rolls a 18 and hits
Goblin 6 must make two saving throws. He rolls a 1 and 9, fails them both and dies.
Goblin 2 can't attack, he is picking up a short sword
Goblin 3 can't attack, he is picking up a military pick
Goblin 4 attacks centipede 1, rolls a 10
Goblin 5 attacks centipede 8, rolls a 17 and kills it
Goblin 6 just died
Goblin 7 attacks centipede 8, rolls a 15 and hits, but it is already dead
End of round 2. We have 3 centipedes left and 5 goblins left. For actions it is all melee. Centipedes roll a 5 for initiative and goblins roll a 6.
Goblin 2 attacks centipede 6, rolls a 13 and hits for 2 points, killing it
Goblin 3 attacks centipede 6, rolls a 7
Goblin 4 attacks centipede 6, rolls a 7
Goblin 5 attacks centipede 4, rolls a 1
Goblin 7 attacks centipede 1, rolls a 8
Centipede 1 attacks goblin 3, rolls a 3
Centipede 4 attacks goblin 5, rolls a 13
On to Round 4. Same actions. Centipedes get a 5 for initiative and the goblins get a 3.
Centipede 1 attacks goblin 2, rolls a 9
Centipede 4 attacks goblin 5, rolls a 11
Goblin 2 attacks centipede 4, rolls a 16 and hits for 4 points of damage, killing it
Goblin 3 attacks centipede 4, rolls a 20 and hits but it is already dead
Goblin 4 attacks centipede 4, rolls a 14 and hits but it is already dead
Goblin 5 attacks centipede 1, rolls a 2
Goblin 7 attacks centipede 1, rolls a 19 and hits for only 1 point of damage, but that is enough to kill it.
Well it took four rounds and 2 goblins died to clear out a room of 8 giant centipedes. I figured it might go this way but I thought goblin casualties would be higher.
One of the reasons this fight intrigued me was that I suspected that giant centipedes are not as tough as the standard level II monster. Certainly other such monsters, such as gnolls, troglodytes, etc. would fare better against the goblins here.
A goblin can kill a giant centipede on a single attack just under 45% of the time. They hit on an 11 or better (45%) and they almost always do more than 1 point of damage. Even if they ALWAYS did exactly 1 point of damage they kill a giant centipede ½ of the time.
Giant centipedes, however, kill goblins only by hitting (needing a 15, or 25% of the time) and then having the goblin fail the save (which happens 55% of the time). That is only a 13.75% chance to kill in one round.
Giant centipedes do remain a relative threat as their opponents become more powerful, paradoxically. A single goblin is not a credible threat to a 5th level adventurer (unless they rolled all 1's for hit points) but a giant centipede can kill a 5th level adventurer in one hit, even though it is not likely.
If the 5th level adventurer is a fighter, he or she probably has an armor class of 2 or better and saves against giant centipede poison on a 7 or better. The giant centipede would kill in one round at a (10% for to hit AC 2 X 30% of failing save) 3.0% chance. This is much less than the chance to kill a goblin, but it is not zero.
If it is a magic-user, he or she probably has an AC of 8 or so, maybe better if the found some good magic items of protection. The centipede will hit on a 13 (35% chance) and the magic-user must fail the save (50% chance). That is 17.5 % (higher than the goblin!) Of course, this will go down drastically if the magic-user has a high dexterity and magic protection.
For level 5 clerics, (assuming AC 2 again), the chance of death is only 2.0%, and for level 5 thieves (assuming AC 6), it is 8.75%. When dwarves, gnomes, or halflings are the targets, survival rates increase dramatically, due to their excellent poison saving throws. I suppose when fighting giant centipedes, have clerics, fighters, and wee demi-humans do it.