Short answer. They are deemed admitted. Material averments in a claim pleading that the answer does not specifically deny are treated as admitted, and no evidence is needed to prove them at trial. The one carve-out is the amount of unliquidated damages, which must always be proved even if not denied.
What the law says
Material averments in a pleading asserting a claim or claims, other than those as to the amount of unliquidated damages, shall be deemed admitted when not specifically denied.
Rule 8, Section 11 — Allegations not specifically denied deemed admitted. Read the full provision →
Silence is admission
The rule is a single sentence with sharp teeth: material averments in a pleading asserting a claim or claims, other than those as to the amount of unliquidated damages, shall be deemed admitted when not specifically denied. Pleadings exist to mark out what the parties actually dispute; whatever the answer leaves unchallenged is taken off the table as settled. The plaintiff no longer has to prove a deemed-admitted fact, the defendant can no longer contest it, and the trial — if one is still needed — is confined to what was genuinely denied.
What a denial has to do to count
The operative word is specifically. A denial does its job when it engages the particular allegation — identifying what is denied and, where the defendant relies on a different version of events, setting out the substance of it. Blanket formulas that purport to deny everything at once, or denials so evasive they never actually meet the allegation, risk being treated as no denial at all. The consequence is severe precisely because it is automatic: nobody has to move to have the fact established — the rule deems it admitted by operation of law.
The carve-out: unliquidated damages
One category escapes the rule: the amount of unliquidated damages. Amounts that are not fixed or ascertainable from the claim itself — moral damages, for instance, or other sums whose size a court must assess — must be proved with evidence even if the answer says nothing about them. Note how narrow the carve-out is: it covers the amount, not the underlying facts. An unanswered allegation about what the defendant did can still stand admitted; what the plaintiff must always establish is how much that conduct should cost.
What to do about a defective answer
Which side of this rule you are on dictates the move. A plaintiff should map each material allegation against the answer and mark what was never specifically denied — those admissions can anchor a motion to shortcut the trial or narrow it dramatically. A defendant who spots the gap in their own answer should raise it with counsel immediately and ask whether the pleading can still be corrected; the earlier that conversation happens, the more room there is. Either way, the comparison of complaint against answer, paragraph by paragraph, is the first task.