Can an appellate court overturn part of a decision not appealed against?
<p>Bob litigates against Rob. The case boils down to resolving two questions of law: X (rather critical to Bob) and Y (not so critical). The two questions are separate/isolated, although both are highly relevant to the facts.</p>
<p>Bob wins on question X (and hence, substantial/material relief against Rob follows) but fails to convince the judge to take his view on question Y (not a big deal but somewhat disappointing to Bob).</p>
<p>Bob takes the judge's decision to appellate court to appeal on question Y only.</p>
<p>Can the appellate court review question X on its own volition and overturn the decision on X reached by the lower court, effectively making Bob shoot himself in the leg?</p>
<p>If not, can the appellate court do that if Rob argues for it in his response to Bob's appeal on Y?</p>
<p>(Any jurisdiction with <a href="https://en.wikipedia.org/wiki/Adversarial_system" rel="nofollow noreferrer">adversarial system</a>. Case law examples would be very good.)</p>

<p>You have asked two quite different questions there. I’ll address the second part first (where Rob argues for the decision in Bob’s favour to be overturned in his response to Bob's appeal), because it’s easier. For both parties to partially succeed at trial, and both parties to contend on appeal that they should have been wholly successful, is not that unusual. It is usually called a cross-appeal in Commonwealth jurisdictions, or in the Supreme Court of the United States, a cross-petition.</p>
<p>An example from the United Kingdom: in <a href="https://www.supremecourt.uk/cases/docs/uksc-2014-0125-press-summary.pdf" rel="nofollow noreferrer"><em>R (on the application of Carmichael and Rourke) v Secretary of State for Work and Pensions</em></a> [2016] UKSC 58, the court dealt with four appeals arising out of challenges to the so-called <a href="https://en.wikipedia.org/wiki/Bedroom_tax" rel="nofollow noreferrer">bedroom tax</a>. In one case, the claimant succeeded on one of two grounds, the government appealed, and the claimant cross-appealed on her failed ground:</p>
<blockquote>
<p>The Rutherfords succeeded in their claim on the ground of disability discrimination. [Ms A’s] claim succeeded on the grounds of sex discrimination. Both A’ and the Rutherfords’ Equality Act claims were rejected. The Secretary of State appeals the Court of Appeal’s decision to allow the Rutherfords’ and A’s discrimination claims. A cross-appeals the rejection of her Equality Act claim … The Secretary of State’s appeal in respect of A is allowed, and A’s cross appeal is dismissed, by a majority of 5 to 2.</p>
</blockquote>
<p>The first part of your question is more difficult, which is why you have received two conflicting answers. Usually appellate courts have the formal power to go beyond the issues raised by the parties, as pointed out by @Dale M. In any event, if an apex court exceeds its powers, there is no further court of appeal to say so. However, as @ohwilleke points out, to decide the case on a ground not argued violates due process. When an appellate court does this, it is said to act “on its own motion” or <a href="https://en.wikipedia.org/wiki/Sua_sponte" rel="nofollow noreferrer"><em>sua sponte</em></a>.</p>
<p>As @ohwilleke says, in the United States, appellate courts may be able to <em>affirm</em> the trial court’s decision for any reason supported by the record, even if not raised by any party. This is the “right for any reason” or <a href="https://en.wikipedia.org/wiki/Tipsy_Coachman" rel="nofollow noreferrer">tipsy coachman</a> doctrine. However, your question asks whether a court can <em>overturn</em> part of decision not appealed against. That is, by appealing his partial win, does Bob run the risk of the court ruling <em>sua sponte</em> that he ought to have suffered a complete loss?</p>
<p>This is discussed in Miller, ‘<a href="https://heinonline.org/HOL/LandingPage?handle=hein.journals/sanlr39&amp;div=41&amp;id=&amp;page=" rel="nofollow noreferrer">Sua Sponte Appellate Rulings: When Courts Deprive Litigants of an Opportunity to Be Heard</a>,’ 39 <em>San Diego Law Review</em> 1253 (2002). In the introduction, Miller observes:</p>
<blockquote>
<p>In fact, some of the Supreme Court's most famous opinions decided issues not presented by the briefs or addressed below. In <a href="https://en.wikipedia.org/wiki/Erie_Railroad_Co._v._Tompkins" rel="nofollow noreferrer"><em>Erie Railroad v. Tompkins</em></a>, the Court overturned sua sponte an ancient precedent on applying the common law in diversity cases. <a href="https://en.wikipedia.org/wiki/Mapp_v._Ohio" rel="nofollow noreferrer"><em>Mapp v. Ohio</em></a> overrules a prior case and applied the Fourth Amendment exclusionary rule to the states, without briefing or argument on the issue. In <a href="https://en.wikipedia.org/wiki/Washington_v._Davis" rel="nofollow noreferrer"><em>Washington v. Davis</em></a>, the Court decided that Title VII standards did not apply to constitutional discrimination, even though the parties had agreed that they did. <a href="https://en.wikipedia.org/wiki/Younger_v._Harris" rel="nofollow noreferrer"><em>Younger v. Harris</em></a> prohibits injunctions against pending state court criminal cases, even though the issue was not argued on appeal. Indeed, in <a href="https://en.wikipedia.org/wiki/Stanley_v._Illinois" rel="nofollow noreferrer"><em>Stanley v. Illinois</em></a>, the Court held that due process requires hearings and an opportunity to make submissions before a state can terminate the parental rights of unwed fathers. But the Court decided this without briefing or argument – without a hearing on the issue or an opportunity for the parties to make submissions.</p>
</blockquote>
<p>Most of those cases involve a petition for certiorari in which the petitioner got more than they asked for. However, <em>Younger v. Harris</em> is closer to the Bob/Rob scenario. Younger, the <a href="https://en.wikipedia.org/wiki/Los_Angeles_County_District_Attorney" rel="nofollow noreferrer">District Attorney of Los Angeles County</a>, prosecuted Harris under the <a href="https://en.wikipedia.org/wiki/California_Criminal_Syndicalism_Act" rel="nofollow noreferrer">California Criminal Syndicalism Act</a>. Before the criminal trial, Harris sued Younger in the Federal District Court, which held the Act void for vagueness and overbreadth, and enjoined the prosecution. Younger appealed to the Supreme Court, but rather than determining whether the Act was constitutional, the Supreme Court reversed the district court’s decision on the ground that federal courts should only enjoin state criminal prosecutions in extraordinary circumstances. So, Younger “won,” but Harris’s constitutional argument remained open and supported by the district court’s opinion, which Younger could not challenge again without first securing a conviction at trial.</p>
<p>To summarise, appellate courts sometimes do overturn decisions based on arguments not raised by the parties. However, this is exceptional and is generally considered procedurally unfair. If an appellate court thinks the parties have missed an important legal argument, it is more common and appropriate for the court to raise it at the hearing, and invite the parties to consider and make submissions about it.</p>

<h2>Yes</h2>
<p>For example, s51.52 of the <a href="/questions/tagged/new-south-wales" class="post-tag" title="show questions tagged &#39;new-south-wales&#39;" rel="tag">new-south-wales</a> <a href="https://www.legislation.nsw.gov.au/view/html/inforce/current/sl-2005-0418#sec.51.52" rel="nofollow noreferrer">Uniform Civil Procedure Rules 2005</a> explicitly gives this power to the court.</p>
<blockquote>
<p>(1)  The Court may exercise its powers under the Civil Procedure Act 2005, the Supreme Court Act 1970 and these rules even if—</p>
<p>(a)  there is no appeal from some part of the decision below, or</p>
<p>(b)  a party to the proceedings below has not appealed, or</p>
<p>(c)  a ground for allowing or dismissing the appeal or varying the decision is not included in any notice of appeal, notice of cross-appeal or notice of contention, or</p>
<p>(d)  there has been no appeal from some other decision in the proceedings.</p>
</blockquote>

<p>In a direct appeal in the U.S. to an intermediate court of appeal, or an appeal of right to a supreme court, the court doesn't decide which issues are being considered.</p>
<p>Appellate procedure calls for a court to only consider challenges to the judgment below raised by the party that appeals in both the trial court and appellate court. But, the court can affirm for any reason supported by the record, even if not raised by any party at any time.</p>
<p>Usually, a supreme court hearing a discretionary cert petition will only consider issues upon which it granted cert, but it can change its mind regarding what it will grant cert upon before its final ruling. Usually if it does so, it will ask for additional briefing before ruling on the additional issue to afford all sides due process and a chance to argue the issue fully.</p>

rules-of-court litigation appeal