COLLINS, Justice.
Ferraiolo Construction Co., Inc. (“Fer-raiolo”) appeals from a summary judgment in the Superior Court (Cumberland County, Fritzsche, J.) in which it is declared that Ferraiolo’s comprehensive general liability insurer, Massachusetts Bay Insurance Company, has no duty to defend nor indemnify Ferraiolo from certain claims (“the Coffey suit”) brought against it by William Coffey and others.1 Because the Superior Court erred in its application of the law, we vacate the judgment.
The plaintiffs in the Coffey suit, which is still pending, allege that Ferraiolo operated its gravel pit in the town of Washington in such a fashion as to trespass upon their land. They seek damages both for common-law trespass and for violation of 14 M.R.S.A. § 7552 (injury to lands or property). Ferraiolo tendered the Coffey suit to the insurance company and requested it to defend. The insurance company declined to do so and filed this action seeking a declaratory judgment that it had no duty to defend the Coffey suit, nor to indemnify Ferraiolo for any liability incurred in the suit.
Construing the policy coverage in light of the distinction between “occurrence of harm risk” and “business risk” that we adopted in Peerless Insurance Co. v. Brennon, 564 A.2d 383 (Me.1989), the Superior Court held that Ferraiolo sought coverage for a “business risk” not covered by the policy. The court also decided that the alleged trespass, even if based merely on “mistake or error as to the ownership of the property,” would not be an “occurrence” covered by the policy. The court therefore granted summary judgment for the insurance company. The court did not reach the insurance company’s additional contention that the property was excluded from coverage because it was either property “occupied by ... the insured” or “property, not on premises owned by or rented to the insured ... upon which operations are being performed by ... the insured.” Ferraiolo now appeals.
I.
The language of liability insurance policies is standardized throughout the insurance industry. See Patrons-Oxford Mutual Insurance Co. v. Dodge, 426 A.2d 888, 890 (Me.1981); Weedo v. Stone-E-Brick, 81 N.J. 233, 405 A.2d 788, 790 (1979). The insured can negotiate only particular standard riders or exclusions. See R. Keeton, Basic Text on Insurance Law (1971), §§ 2.10, 2.11 at 68-87. Accordingly, a liability insurance policy must be construed so as to resolve all ambiguities in favor of coverage. “[A] standard policy of insurance ... being the crafty product of insurers who made the policy, selected its language and ordained its particular structure, should be interpreted most strongly against the insurer.” Baybutt Construction Corp. v. Commercial Union Insurance Co., 455 A.2d 914, 921 (Me.1983).
The insurer’s duty to defend the insured against third-party claims is determined by comparing the insurance policy against the complaint. If the complaint shows even a possibility that the events giving rise to it are within the policy coverage, the insurer must defend the suit. Any ambiguity must be resolved in favor of a duty to defend. See Union Mutual Fire Insurance Co. v. Inhabitants of Town of Topsham, 441 A.2d 1012, 1015 (Me.1982).
1
William Coffey, James Coffey, Albert Mortali, Susan M. Morang, and Vincent Mecca, plaintiffs in the Coffey suit, were named as parties in interest in the declaratory judgment action in the Superior Court, but are not parties to this appeal.