By Alan McCoy from Dungeons & Dragons: Fundamentals
How to build challenging encounters against a Giant Spider
Note: This has been prepared utilizing only the 5E Core Rules. This essay will cover only the Giant Spider (MM page 328).All spiders are predators, the Giant Spiders included. Like their naturally occurring brethren, Giant Spiders build webs and wait for prey, they can also shoot strands of webbing from their abdomen.
Neither this essay, nor the Monster Manual is intended to be an exhaustive study of spiders. Individual DMs are free to utilize ‘Giant’ versions of any naturally occurring species that they find interesting.Communal Spider species, though found in nature, are not good candidates for ‘Giant Size’. Such a group would rapidly consume even a prolific ecology.
Intelligent Spiders, or spiders with magical or magic-like abilities may have some similarities with the beasts portrayed here, but those creatures are beyond the scope of this essay.It is my opinion that the designers of the game have done a horrible job in portraying this creature. As designed, it reminds me of the huge Spider in the Gilligan’s Island episode (Season 3 – The Pigeon).
The beast itself is weak, probably to maintain the status of a challenge rating one creature. Additionally, is a failure to provide any information on the web and how the beast would utilize it in a fight. I will be suggesting web-based tactics to utilize, even though I admit that these additions are not a part of RAW.
Because this web using monster, once discovered, is easy to avoid, it is important to consider how and why one might be encountered. Intelligent Monsters will transplant and will often feed these creatures to keep them from moving on. They are an excellent passive defense measure to guard unused approaches to your lair, or perhaps they guard an escape route.
Step 1 — Lets review what we know about the Giant Spider
Appearance: While almost any naturally occurring web building spider species can be utilized to provide specific description, it is important to gain an appreciation of size: A giant spider occupies a 10 foot X 10 foot combat square (vs a humans 5X5), so roughly five foot body size, the legs extending outwards, massing 750 lbs. or so.
Spiders are Strong, Dexterous and Tough.
Despite their Giant Size, spiders are skilled in stealth.
Spiders build webs.
Spider movement is unaffected by difficult surfaces, they can even move up or down walls and upside down on ceilings with no movement penalty. They can of course move freely on their web.
Spider Senses include: Blindsight 10′(the ability to see by feel and sound), Darkvision 60′ and Web Sense (knows the exact location of any creature touching its web, if in contact with the web.)Spiders have a poisonous bite.
Spiders can shoot webbing from its abdomen.
Step 2 — Determine Probable Strategy: What do spiders want and how do they get it?
Giant Spiders have two primary instinctual drives: Food and Self-Preservation. By instinct, giant spiders build elaborate webs in which to snare prey. This web also serves as an early warning system. In short, giant spiders do not hunt as much as trap some or all the traffic that passes near them.
Step 3 — Determine Probable Tactics: RAW
Unless you are snared in a giant spider’s web, you will probably never encounter them. Giant spiders do not seek out prey that hasn’t fallen into their web.
If you do get snared in the giant spider’s web, it will investigate. Once its target is located, it will attempt to snare from a distance with a webbing discharge. Once the target is secure, it will close to the target and bite.
The webbing discharge has a short range of 30′ and a maximum range of 60′, this means that any shot at a range greater than 30′ is at disadvantage. This ability has a recharge of d6 (5-6). This means that once used, the web discharge is unusable until a 5 or 6 is rolled on a d6.
If hit by a webbing discharge, the target is restrained. As an action, the restrained target may attempt to struggle and break free or allies may attempt to attack the webbing.
Spider Bite: The spider will bite a restrained target (with Advantage), it’s bite does piercing damage and causes poison damage. Once a target drops to zero hit points it stabilizes but is subjected to both the poisoned and the paralyzed conditions for the next hour, even if hit points are regained.
The Spider will utilize its webbing to fully restrain a poisoned target and will give an occasional nip to keep the target from struggling and disturbing its web until it decides to eat the victim.
Step 3) Determine Probable Tactics (My Way — FYI if you use my way the Giant Spider should be a CR 3)
Giant Spiders construct large elaborate webs in ecosystems that have a enough prey to support their appetite, roughly one large, two medium, four small or eight tiny creatures each week.
Their lair can be underground but is far more likely to be placed in the canopy of a forest or across a canyon. The lair will have several outlying ‘signal’ strands to warn the giant spider of any approach to its lair.
The Web itself consists of rope like strands arrayed in the elaborate concentric pattern we all know so well. The strands of this web glisten with moisture, because of this, the webbing will not easily ignite. (Despite the oft repeated rumors…which apply to dry abandoned webs).
Some of the webbing is safe to touch, some of it is sticky. (Survival Check DC 16, Investigation Check DC 18 to determine). Checks will need to be made each round when moving on the web.
If a sticky strand is touched, DC 17 Strength check will be needed to free the body part. DC 15 Survival check during the process or another body part will become stuck, even if the original body part is freed. The strength check DC increases by 4 for everybody part that becomes stuck. A check is allowed each round.
Struggling in the web for three consecutive rounds requires a CON check DC 10 or a level of exhaustion will be applied. The Spider will be aware of the struggles on its web but will allow the victim to continue to struggle until it tires. The ideal victim has three levels of exhaustion.
If a victim is being rescued or appears to be breaking free, the spider will use its web discharge (increase range to 60/120). It might choose to use the discharge on a rescuer and attempt to capture both.
Once a victim is exhausted, the spider will approach and bite to poison the victim. Remember that the bite is with advantage due to restraint, and that the exhausted victim might have disadvantage on saving throws. The bite does pierce damage and causes poison damage. Once a target drops to zero hit points it stabilizes but is subjected to both the poisoned and the paralyzed conditions for the next hour, even if hit points are regained.
The Spider will utilize its webbing (no recharge because it’s not being projected) to fully restrain a poisoned target and will give an occasional nip to keep the target from struggling and disturbing its web until it decides to eat the victim. It won’t be long…
Changes to the Spider
Increase AC 17 (Chitin equivalent to Banded Mail + Dexterity)
Increase Health to 6d10+6 (Average 39)
Increase Movement Speed to 50 ft / climb 50 ft
Changes to Web Strand: AC 12, HP 10
Immune to bludgeon, force, piercing, poison, and psychic damage.
No Vulnerabilities.
If attempting to free a restrained victim, the victim will receive identical damage, DC 12 Dexterity save for 1/2 damage.