The spell Stone Spiders (FRCS, p. 75) reads:

You transform 1d3 pebbles into stone constructs that resemble monstrous spiders. The constructs can be any size from Tiny to Huge as you decide, but all the constructs you create must be the same size. The constructs have the same statistics as monstrous spiders (see Appendix 2 in the Monster Manual) of the appropriate size, except as follows:

Their natural armor increases by +6.

They have damage reduction 30/+2.

Their poison has a Fortitude save DC of 17 + your Wisdom modifier. Initial and secondary damage is 1d3 points of temporary Strength damage.

This seems pretty straightforward. But the MM (p. 307) says on constructs:

Features: A construct has the following features.

  • 10-sided Hit Dice
  • Base attack bonus equal to 3/4 Hit Dice (as cleric).
  • No good saving throws.


Traits: A construct possesses the following traits (unless otherwise noted in a creature’s entry).

  • No Constitution score.
  • Low-light vision.
  • Darkvision out to 60 feet.
  • Immunity to all mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects).
  • Immunity to poison, sleep effects, paralysis, stunning, disease, death effects, and necromancy effects.
  • [...]
  • Not subject to critical hits, nonlethal damage, ability damage, ability drain, fatigue, exhaustion, or energy drain.
  • Immunity to any effect that requires a Fortitude save (unless the effect also works on objects, or is harmless).
  • Not at risk of death from massive damage [...]. Immediately destroyed when reduced to 0 hit points or less. [...]

The MM also attributes bonus HP to constructs based on Size.

If you apply all these traits and features to the Monstrous Spider, you get a creature that in almost no way has "the same statistics" of the Monstrous Spider.

A Huge "Stone Spider" would look like this:

Huge Construct
Init +3 (+3 dex)
AC 22 FF 19 Touch 11 (-2 size, +3 Dex , +11 natural)
HD: 8
HP: 84 (8d10+40)
DR 30/+2
Fort +2 (immunity to all effects unless effecting objects) Ref +5 Will +2 (immunity to all mind-effecting effects)
Speed 30 ft. (6 squares), climb 20 ft.
Base Atk +6 Grp +18
Attack: Bite +8 2d6+6 plus poison DC 23 (1d3 Str/1d3Str)
Full Attack: Bite +8 2d6+6
Space 15 ft. (3 squares) Reach 10 ft. (2 squares)
Abilities Str 19(+4) Dex 17(+3) Con -- (+0) Int -- Wis 10(+0) Cha 2(-4)
Darkvision(Ex): 60 ft.
tremorsense(Ex): 60 ft.
Low light vision
Immunity to all mind-effecting effects, poison, sleep, paralysis, death, stunning, disease, necromancy, critical hits, non-lethal damage, ability damage, ability drain, fatigue, exhaustion, energy drain all effects that require a Fort save (unless affecting objects).

On the other hand: If you took the spell literally, you would get a construct with a Constitution score, something very strange indeed.

Do you really go with the Monstrous Spider stats? Or do you apply construct traits to the Monstrous Spider (apart from the DR which is explicitly set in the spell)?

  • \$\begingroup\$ It doesn't matter for the question, but the Spell Compendium updates the spell so that a level 13 cleric won't cast this spell and create a random number of construct vermin anymore—the update changes it to a flat three construct vermin (209). \$\endgroup\$ Commented Oct 13, 2019 at 18:58

3 Answers 3


Constructs don’t have Constitution scores. When the description says that they “are constructs,” that is telling you that you should give them all of the construct traits—including Constitution non-ability.

Should the book have specified that again when saying to use monstrous spider stats? Absolutely it should have. Can you make an argument that, rules as written, the monstrous spider statblock’s indication of the vermin type overrides the statement that they are constructs? Sure, though I don’t consider it a very strong case—you can’t have something that “is a construct” but lacks the construct type, so that argument basically requires ignoring the initial description—potentially RAW-valid, if you hold that the later introduction of monstrous spider stats overrides it, but then you have to wonder why it’s there at all.

But what it ultimately comes down to is they made a mistake and neglected to mention the construct type again—maybe they thought it unnecessary, maybe they just forgot, but it should have been there. Their mistake isn’t a great reason to introduce broken or nonsensical material to your game.

  • \$\begingroup\$ Giorin is citing the FRCS version, which would presumably be subject to the type period from Savage Species. That makes vermin overriding construct even more dubious. \$\endgroup\$
    – fectin
    Commented Oct 15, 2019 at 2:28

RAW, The Spiders aren't constructs, they are vermin

The spell's statblock says that the spiders are like monstrous spiders except for the listed adjustments:

Their natural armor increases by +6. They have damage reduction 30/+2. Their poison has a Fortitude save DC of 17 + your Wisdom modifier. Initial and secondary damage is 1d3 points of temporary Strength damage.

Notably, nowhere is the base monster's creature type changed to construct. So, while the Stone Spider is a construct, it does not have the 'construct' type.

You should probably ignore that, though

While it's not against the rules to have a construct that lacks the 'construct' type (e.g. many undead are artificially constructed beings), and while that is wht the text actually says, it's pretty contrary to how the spell is initially described. The Construct type is also usually better than the Vermin type except when you are trying to combo with stuff to break the game, so you should definitely consider allowing this 7th level Spider-only spell to generate creatures with the benefits of the Construct type.

Be aware, however, that in house ruling this way you need to decide if you should recalculate Saves, BAB, and hp for the new type-- some effects have you do that and some don't, and you are essentially creating a new effect. It makes somewhat more sense to do recalculations here than not to, since the creatures aren't actually modifications to an existing creature but merely based off their stats, but it is also a bit of work so you should make sure your players do that correctly and also outside of play time, probably.

  • \$\begingroup\$ I have difficulities accepting the "there are constructs that do not have the Construct type" point. Because only with this in mind could the wording of the spell refer to anything else than a change of type. Could you give specific examples of such "constructs without Construct type"? \$\endgroup\$
    – Giorin
    Commented Oct 13, 2019 at 21:05

Rules As Written, use the spider hp and stats

A literal reading of the rules tells us that we take the spider stats and make a small number of modifications. Thus a huge stone spider has 52hp, a bite attack at +9, and is not immune to death effects. It's not clear whether this creature has type "vermin" or "construct" -- it depends on whether the spell description calling this a "construct" overrides its instruction to copy the spider stats -- but even if its type is "construct", it doesn't get the immunities or bonus hit points (or worse saves) that all other constructs get.

A DM might issue a house rule here for consistency

If a DM is uncomfortable with having these stone "constructs" lack all the construct traits, it would be very reasonable to house rule some or all of the traits onto the construct.

The DM should think carefully before issuing a house rule that changes the spiders' hp, since this would significantly change the balance of the spell.


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