United States Court of Appeals 

for the Federal Circuit ______________________ 

WORLDS INC.,

Appellant

v.

BUNGIE, INC.,

Appellee

______________________ 

2017-1481, 2017-1546, 2017-1583

______________________ 

Appeals from the United States Patent and Trademark Office, Patent Trial and Appeal Board in Nos. 

IPR2015-01264, IPR2015-01319, IPR2015-01321.

______________________ 

Decided: September 7, 2018

______________________ 

 WAYNE MICHAEL HELGE, Davidson Berquist Jackson 

& Gowdey, LLP, McLean, VA, argued for appellant. Also 

represented by GREGORY A. KRAUSS, ALDO NOTO. 

 MICHAEL T. ROSATO, Wilson, Sonsini, Goodrich & 

Rosati, PC, Seattle, WA, argued for appellee. Also represented by MATTHEW A. ARGENTI, Palo Alto, CA; RICHARD 

TORCZON, Washington, DC.

______________________ 

Before PROST, Chief Judge, O’MALLEY and TARANTO,

Circuit Judges.
2 WORLDS INC. v. BUNGIE, INC. 

PROST, Chief Judge. 

Appellant Worlds Inc. (“Worlds”) appeals the final decisions of the Patent Trial and Appeal Board (“Board”) 

invalidating three patents in three inter partes reviews 

(“IPRs”). Because we hold that the Board erred in its 

real-party-in-interest analysis, we vacate its decisions and 

remand for proceedings consistent with this opinion. 

I 

This consolidated appeal involves three related patents: U.S. Patent Nos. 7,945,856 (“the ’856 patent”); 

8,082,501 (“the ’501 patent”); and 8,145,998 (“the ’998 

patent”) (collectively, the “patents-on-appeal”).1 These 

patents generally relate to the computer-generated display of avatars in a virtual world, including methods and 

systems to determine which particular avatars are displayed in a given situation. 

In 2012, Worlds asserted the patents-on-appeal, 

among other patents, against Activision Publishing, Inc. 

(“Activision”) and other related entities in the District of 

Massachusetts. J.A. 2992–3002 (Compl.), 4902–04 (Am. 

Compl.). Activision develops, publishes, licenses, and 

distributes videogames. In the district court litigation 

against Activision, Worlds accused certain videogames, 

such as Call of Duty, of infringing claims of Worlds’s 

patents. 

Appellee Bungie, Inc. (“Bungie”) is an independent 

videogame developer that has developed games such as 

Halo. Bungie also developed the series of products relevant to these appeals—the Destiny products. Destiny is 

developed by Bungie and distributed by Activision. 

 

1 The case numbers of the IPRs on appeal are: 

IPR2015-01264 (the ’856 patent); IPR2015-01319 (the ’501 

patent); and IPR2015-01321 (the ’998 patent). 
WORLDS INC. v. BUNGIE, INC. 3

Bungie is not a party to the litigation between Worlds 

and Activision. In November 2014, however, Worlds 

notified Activision that it intended to add Destiny as an 

additional accused product in the district court litigation. 

J.A. 2944. Approximately six months after Worlds notified Activision of its intent to add Bungie’s products to the 

litigation, Bungie filed six IPR petitions, including the 

three IPRs at issue in this case, challenging Worlds’s 

patents.2 These petitions were filed more than one year 

after Activision had been served with a complaint alleging 

infringement of the patents challenged in the IPR petitions. 

Soon after Bungie filed its IPR petitions, Worlds 

moved under 37 C.F.R. § 42.51(b) for routine discovery or, 

alternatively, additional discovery, requesting information regarding whether Activision should have been 

named as a real party in interest to the proceedings, thus 

making the petitions time-barred under 35 U.S.C. 

§ 315(b). J.A. 394–405.3 To support its request for discovery, Worlds submitted evidence of a Software Publishing and Development Agreement (“DevPub Agreement”) 

between Bungie and Activision.4 

The DevPub Agreement provides that the Destiny

products would be developed by Bungie and published by 

Activision. Under the Agreement, Bungie is responsible 

for conducting “legal reviews of the Products to ensure 

 

2 The case numbers of the IPRs that are not on appeal are: IPR2015-01325 (the ’998 patent); IPR2015-

01268 (U.S. Patent No. 7,181,690); and IPR2015-01269 

(U.S. Patent No. 7,493,558). Worlds did not appeal the 

final written decisions in these three IPRs.

3 The same motion was filed in all six pending 

IPRs. J.A. 394 n.1.

4 Worlds discovered the DevPub Agreement 

through its own independent investigation. See J.A. 400.
4 WORLDS INC. v. BUNGIE, INC. 

that all Intellectual Property and other rights are fully 

cleared for use.” J.A. 2924. Such “legal reviews” are

“subject to prior review and approval of Activision, (budget to [sic] mutually approved) such approval not to be 

unreasonably withheld.” Id. The Agreement also contains certain representations and warranties, as well as 

indemnity provisions. J.A. 2933–36. And, the Agreement 

contemplates financial support from Activision to Bungie 

for development of the Destiny products. J.A. 2928–29. 

Based on the DevPub Agreement, Worlds’s discovery 

motion contained six specific requests for production 

seeking further details of the relationship between Activision and Bungie. J.A. 394–97. Bungie opposed the

motion for discovery, J.A. 407–18, and the Board denied 

the motion in its entirety, J.A. 423–32. In doing so, the 

Board concluded that Worlds had not shown more than a 

“mere allegation” that something useful would have been 

found through the requested discovery. J.A. 430. 

Four days later, Worlds filed its pre-institution Preliminary Response, arguing that Bungie should have 

named Activision as a real party in interest. J.A. 434–77, 

3841–49, 5047–57. In its decisions to institute, the Board 

rejected Worlds’s argument, concluding that “Patent

Owner has not demonstrated that Activision is an unnamed real party in interest in this proceeding.” J.A. 511, 

3878, 5095. 

The Board issued final written decisions in these 

three IPRs on November 10, 2016; November 28, 2016; 

and December 6, 2016. In these final decisions, the Board 

reiterated its rejection of Worlds’s real-party-in-interest 

argument by referring back to the analysis in its institution decisions. J.A. 106–07, 194–95, 258–59. Finding the 

petitions not time-barred, the Board proceeded to address

the patentability of the instituted claims.
WORLDS INC. v. BUNGIE, INC. 5

Worlds timely appealed each final written decision. 

We have jurisdiction pursuant to 28 U.S.C. 

§ 1295(a)(4)(A). 

II

This consolidated appeal presents two issues. First, 

Worlds contends that Bungie’s IPR petitions were timebarred because an alleged real party in interest, Activision, had been served with a complaint alleging infringement of these patents over one year prior to the 

IPRs’ filing dates. Second, Worlds appeals the Board’s 

substantive obviousness analysis. 

A 

Under 35 U.S.C. § 312(a)(2), an IPR petition “may be 

considered only if . . . the petition identifies all real parties in interest.” Correctly identifying all real parties in 

interest with respect to each IPR petition is important, as 

the determination may impact whether a petition may be

instituted. See 35 U.S.C. § 315(a)(1) (concerning a real 

party in interest’s civil action challenging the patent’s 

validity); id. § 315(b) (concerning a patent owner’s civil 

action against a real party in interest). It may also limit 

the arguments available in subsequent proceedings. See 

id. § 315(e). In this case, Worlds argues that Bungie’s

IPR petitions were time-barred under § 315(b) because 

they were filed over one year after Worlds served Activision, the alleged real party in interest, with a complaint alleging infringement of the challenged patents.5 

 

5 The parties’ briefing in this case occurred prior to 

this court’s en banc decision in Wi-Fi One, LLC v. Broadcom Corp., 878 F.3d 1364 (Fed. Cir. 2018) (en banc). As 

such, Bungie in its briefing relied on Achates Reference 

Publishing, Inc. v. Apple Inc. to argue that the Board’s 

real-party-in-interest determination for purposes of 
6 WORLDS INC. v. BUNGIE, INC. 

On appeal, Worlds contends that the Board placed the 

burden of persuasion on the patent owner to prove that 

Bungie’s petitions were time-barred under § 315(b) because Activision was a real party in interest, and that this 

allocation of the burden was error. These appeals therefore require us to determine the appropriate burden 

framework for analyzing the real-party-in-interest determinations in these IPRs. Worlds has not sought review of 

the Board’s order denying Worlds’s motion for discovery 

on this issue. 

1 

Absent from the Board’s analysis of the real-party-ininterest issue is any clear statement of what, if any, 

burden framework the Board used to analyze the evidence 

presented in these IPRs, including an identification of 

which party the Board viewed as bearing the burden of 

persuasion. 

Both Worlds and Bungie point us to Atlanta Gas Light

Co. v. Bennett Regulator Guards, Inc. as representing a 

burden framework used by other Board panels in the realparty-in-interest analysis. See IPR2013-00453, Paper 88 

(P.T.A.B. Jan. 6, 2015). Although there is no indication 

that the Board relied on Atlanta Gas Light in these appeals, we find it appropriate to begin our analysis with 

that decision, given the parties’ focus on that framework. 

 

evaluating the time bar under § 315(b) is not subject to 

review by this court. 803 F.3d 652, 659 (Fed. Cir. 2015), 

overruled by Wi-Fi One, 878 F.3d at 1367. In Wi-Fi One, 

the court overruled Achates and held that the § 314(d) bar 

on the appeal of the Director’s determination of whether 

to institute an IPR proceeding does not apply to the 

Board’s time-bar determinations under § 315(b), thus 

making such time-bar determinations reviewable on 

appeal. Wi-Fi One, 878 F.3d at 1367.
WORLDS INC. v. BUNGIE, INC. 7

Under Atlanta Gas Light, the Board generally accepts 

an IPR petitioner’s identification of the real parties in 

interest at the time the petition is filed. Atlanta Gas 

Light, Paper 88 at 7 (citing ZOLL Lifecor Corp. v. Philips 

Elec. N. Am. Corp., IPR2013-00606, Paper 13 at 7 

(P.T.A.B. Mar. 20, 2014), which cites 77 Fed. Reg. at 

48,695).6 Atlanta Gas Light explained that this initial 

acceptance “acts as a rebuttable presumption” that benefits the IPR petitioner. Id. Quoting Federal Rule of 

Evidence 301, the Board stated that “[t]he party against 

whom a presumption is directed has the burden of producing evidence to rebut the presumption. But this rule does 

not shift the burden of persuasion, which remains on the 

party who had it originally.” Id. at 8 (quoting Fed. R. 

Evid. 301 (emphasis in Board’s opinion)). From this, the 

Board in Atlanta Gas Light explained that, where “a 

patent owner provides sufficient rebuttal evidence that 

reasonably brings into question the accuracy of a petitioner’s identification of the real parties in interest, the burden remains with the petitioner to establish that it has 

complied with the statutory requirement to identify all 

the real parties in interest.” Id. 

We largely concur with the burden framework used in 

Atlanta Gas Light. As explained below, we agree that the 

IPR petitioner bears the burden of persuasion to demonstrate that its petitions are not time-barred under 

§ 315(b) based on a complaint served on a real party in 

 

6 The Federal Register notice cited in Atlanta Gas 

Light includes the PTO’s responses to public comments. 

In response to a question regarding burdens of proof and 

persuasion in a challenge to the real-party-in-interest 

identification, the PTO stated: “The Office generally will 

accept the petitioner’s ‘real party-in-interest’ identification at the time of filing the petition.” Part III, 77 Fed. 

Reg. 48,680, 48,695 (Aug. 14, 2012). 
8 WORLDS INC. v. BUNGIE, INC. 

interest more than a year earlier. We also agree that an 

IPR petitioner’s initial identification of the real parties in 

interest should be accepted unless and until disputed by a 

patent owner. And although we disagree with treating

this initial acceptance as a “rebuttable presumption” that 

formally shifts a burden of production to the patent 

owner, we agree that a patent owner must produce some 

evidence to support its argument that a particular third 

party should be named a real party in interest. 

At the outset, there can be no doubt that the IPR petitioner bears the ultimate burden of persuasion to show 

that its petitions are not time-barred under § 315(b) based 

on a complaint served on an alleged real party in interest

more than a year earlier. On this point, the relevant 

statute is clear. Under § 556(d) of the Administrative 

Procedure Act (“APA”), “[e]xcept as otherwise provided by 

statute, the proponent of a rule or order has the burden of 

proof.” 5 U.S.C. § 556(d); see also id. § 551(6) (defining 

“order” to mean “the whole or a part of a final disposition, 

whether affirmative, negative, injunctive, or declaratory 

in form, of an agency in a matter other than rule making 

but including licensing”). The Supreme Court has explained that this provision of the APA refers to the burden of persuasion. Dir., Office of Workers’ Comp. 

Programs, Dep’t of Labor v. Greenwich Collieries, 512 U.S. 

267, 276 (1994) (“[W]e understand the APA’s unadorned 

reference to ‘burden of proof’ to refer to the burden of 

persuasion.”). Thus, because the IPR petitioner is the 

party seeking an order from the Board, § 556(d) requires 

the petitioner to bear the burden of persuasion. And, 

while § 556(d) allows for exceptions to be provided by 

statute, no such exception exists here. 

This allocation of the burden of persuasion makes 

sense. First, it is consistent with the general rule that 

“[a]bsent some reason to believe that Congress intended 

otherwise, . . . we will conclude that the burden of persuasion lies where it usually falls, upon the party seeking 
WORLDS INC. v. BUNGIE, INC. 9

relief.” Schaffer ex rel. Schaffer v. Weast, 546 U.S. 49, 57–

58 (2005); see also id. at 57 (indicating that § 556(d) 

reflects the “general rule” that the party seeking court 

action bears the burden of persuasion regarding the 

essential aspects of the party’s claims).7 And as this court 

held in Wi-Fi One, “[t]he timely filing of a petition under

§ 315(b) is a condition precedent to the Director’s authority to act.” 878 F.3d at 1374; see also 35 U.S.C. § 312(a)(2) 

(requiring an IPR petitioner to identify all real parties in 

interest). Second, an IPR petitioner will usually be in a 

better position, at least relative to the patent owner, to 

access evidence relevant to the real-party-in-interest 

inquiry. See United States v. N.Y., New Haven & Hartford R.R. Co., 355 U.S. 253, 256 n.5 (1957) (“The ordinary 

rule, based on considerations of fairness, does not place 

the burden upon a litigant of establishing facts peculiarly 

within the knowledge of his adversary.”). 

Having identified the party bearing the burden of persuasion, we turn to the proper procedure for analyzing 

whether a petition should be time-barred based on a 

complaint served on a real party in interest more than a 

year earlier. As discussed above, the Board in Atlanta 

Gas Light explained that its practice of “initially accepting the identification of real parties in interest in a petition as accurate acts as a rebuttable presumption that 

 

7 Although exceptions to this general rule exist, for 

example, where elements of a plaintiff’s claim “can fairly 

be characterized as affirmative defenses or exemptions,” 

Schaffer, 546 U.S. at 57, we do not view § 315(b) as an 

affirmative defense. Instead, unlike a traditional statute 

of limitations defense, “[t]he timely filing of a petition 

under § 315(b) is a condition precedent to the Director’s 

authority to act,” and “[it] sets limits on the Director’s 

statutory authority to institute.” Wi-Fi One, 878 F.3d at

1374. 
10 WORLDS INC. v. BUNGIE, INC. 

benefits petitioners.” Atlanta Gas Light, Paper 88 at 7. 

Referring to Federal Rule of Evidence 301, the Board 

indicated that such a presumption shifts the burden of 

production to the patent owner, who then must produce 

evidence sufficient to “reasonably bring[] into question the 

accuracy of a petitioner’s identification of the real parties 

in interest.” Id. at 8. 

Initially, we question the Board’s practice of creating 

a “presumption” by its acceptance of a petitioner’s initial 

identification of the real parties in interest. Generally, for 

a party to gain the benefit of a presumption, the party 

must prove certain basic facts from which the presumed 

fact is then inferred according to the relevant substantive 

law. See A.C. Aukerman Co. v. R.L. Chaides Constr. Co., 

960 F.2d 1020, 1035–37 (Fed. Cir. 1992) (en banc) (explaining that the presumption of laches, which was a 

defense available in patent cases prior to SCA Hygiene, 

arose upon proof that the patentee delayed filing suit for 

more than six years after actual or constructive 

knowledge of the defendant’s alleged infringing activity), abrogated on other grounds by SCA Hygiene Prods. 

Aktiebolag v. First Quality Baby Prods., LLC, 137 S. Ct. 

954 (2017); 21B Charles A. Wright & Kenneth W. Graham, Jr., Federal Practice and Procedure: Evidence 

§ 5122 (2d ed. 2005) (“[A] true presumption cannot arise 

without proof of some ‘basic fact’. . . .”). In the real-partyin-interest context at issue here, the relevant statute and 

regulations do not require evidentiary proof of such basic 

facts. See 35 U.S.C. § 312(a)(2) (requiring a petition to 

“identif[y] all real parties in interest”); 37 C.F.R. 

§ 42.8(b)(1) (requiring a party to “[i]dentify each real 

party-in-interest for the party”); see also id. § 42.104(a)

(requiring a petitioner to “certify . . . that the petitioner is 

not barred or estopped from requesting an inter partes

review challenging the patent claims on the grounds 

identified in the petition”). 
WORLDS INC. v. BUNGIE, INC. 11

Moreover, presumptions are usually created based on 

certain policy considerations, such as correcting an imbalance due to one party’s superior access to sources of proof, 

or promoting efficiency by presuming a fact to be true 

where the existence of certain basic facts makes the truth 

of the presumed fact highly probable. See 2 George E. 

Dix, et al., McCormick on Evidence § 343 (7th ed. 2016). 

In the real-party-in-interest context, however, we see no 

particular need to create a formal presumption—

especially a presumption that would disfavor the party

that likely has inferior access to potential sources of proof.

Regardless, we agree that an IPR petitioner’s initial 

identification of the real parties in interest should be

accepted unless and until disputed by a patent owner. 

But instead of viewing this as a presumption, we simply 

view this as practical. In short, we see no reason for the 

Board to question an IPR petitioner’s identification of the 

real parties in interest unless and until a patent owner 

has chosen to raise the issue. 

The next question then becomes: what must a patent 

owner do to sufficiently raise the issue? In Atlanta Gas 

Light, the Board viewed the “presumption” created by the 

IPR petitioner’s initial identification of the real parties in 

interest as shifting the burden of production to the patent 

owner. From this, the Board explained that, where “a 

patent owner provides sufficient rebuttal evidence that 

reasonably brings into question the accuracy of a petitioner’s identification of the real parties in interest, the burden 

remains with the petitioner to establish that it has complied with the statutory requirement to identify all the 

real parties in interest.” Atlanta Gas Light, Paper 88 at 8

(emphasis added). As explained above, we disagree with 

the use of a presumption in this context. We agree, 

however, that a patent owner must produce some evidence 

that tends to show that a particular third party should be 
12 WORLDS INC. v. BUNGIE, INC. 

named a real party in interest.8 A mere assertion that a 

third party is an unnamed real party in interest, without 

any support for that assertion, is insufficient to put the 

issue into dispute. 

2 

In view of this burden framework, we next turn to the 

Board’s analysis of the evidence in this case. In its IPR 

petitions, Bungie listed itself—and only itself—as the real 

party in interest.9 J.A. 354, 3728, 4918. Worlds then 

presented evidence that a particular third party, Activision, was an unnamed real party in interest, including: (1) the DevPub Agreement between Bungie and 

Activision, which related to development of Destiny; 

(2) the November 2014 letter indicating Worlds’s intent to 

add Bungie’s Destiny products to the Activision litigation; 

and (3) the fact that the five patents asserted in the 

Activision litigation were the same five patents Bungie 

challenged in its IPR petitions. 

 

8 For purposes of deciding this case, we need not 

address the quantum of support required from a patent 

owner. If it were not framed in terms of a presumption, 

the standard used in Atlantic Gas Light—evidence that 

“reasonably brings into question the accuracy of a petitioner’s identification of the real parties in interest”—may 

prove useful. In this case, it suffices to say that, as discussed below, Worlds presented more than enough evidence to sufficiently put this issue into dispute. 9 Bungie’s identification of the real parties in interest reads, in its entirety: “Bungie, Inc. is the real partyin-interest.” J.A. 354, 3728, 4918. Given the statutory 

requirement that an IPR petition list “all real parties in 

interest,” 35 U.S.C. § 312(a)(2) (emphasis added), 

Bungie’s statement effectively represents that Bungie is 

the sole real party in interest.
WORLDS INC. v. BUNGIE, INC. 13

Worlds focused much of its argument on Recital 7A.15 

of the DevPub Agreement, which Worlds views as giving 

Activision an opportunity to control the instant IPRs.10 

This provision is found in the section of the DevPub 

Agreement titled “Activision’s Responsibilities” and 

provides that Bungie is responsible for “[c]onducting legal 

reviews of the Products to ensure that all Intellectual 

Property and other rights are fully cleared for use.” 

J.A. 2924, Recital 7A.15.11 The section further provides 

that these legal reviews “shall be subject to prior review 

and approval of Activision, (budget to [sic] mutually 

approved) such approval not to be unreasonably withheld.” Id. From this evidence, Worlds argued before the 

Board that these IPRs are “legal reviews” necessary to 

clear intellectual property rights, and that Activision had 

the opportunity to control the IPRs, making Activision a 

real party in interest. In response, Bungie presented a 

different interpretation of the “legal reviews” provision, 

arguing that, in the context of a videogame development 

agreement, a “legal review[]” refers to “reviewing the title, 

script, and visual and audio assets to ensure that any

appropriate rights have been obtained and that they do 

 

10 Worlds also emphasized other portions of the 

DevPub Agreement, such as the section regarding Activision’s participation in Bungie’s Board of Directors’ 

meetings, J.A. 2938, Recital 18.2, as well as the section

requiring Activision to pay “development advances” to 

Bungie to “fully fund [Bungie’s] operations directly related to the development of the Products,” J.A. 2928–29, 

Recital 10.1. And it also pointed to representations and 

warranties made by Bungie, including that the products 

would not violate the rights of others. See J.A. 2933, 

Recital 14.1.2. 11 “Intellectual Property” is defined in the DevPub 

Agreement to include patents and patent rights. 

J.A. 2919, Recital 6.1. 
14 WORLDS INC. v. BUNGIE, INC. 

not infringe any trademarks or copyrights.” J.A. 415 

(Opp. to Worlds’s Discovery Mot.).12 

The Board flatly rejected Worlds’s argument that

Bungie’s IPRs could be considered “legal review[s] of a 

‘Product,’” first in its order denying Worlds’s discovery 

motion, then again in its institution decisions. J.A. 429 

(Discovery Order) (stating that “[a] legal review of a 

‘Product’ under the Agreement and other provisions do 

not specify, require, or necessarily include filing an IPR 

against a patent”); J.A. 507, 3874, 5092 (Institution 

Decisions) (stating that Worlds’s argument was based on 

a faulty assumption that “legal reviews” could include 

IPRs). The Board’s institution decisions explained that 

the IPRs involved a patent rather than a product, and 

thus the IPRs could not be considered “legal reviews of a 

Product” that would give Activision a right of review and 

approval. J.A. 507 (“The only subject of this proceeding is 

the ’856 patent; this proceeding does not involve any 

product. Thus, Patent Owner has not shown that this 

proceeding falls within the scope of a ‘legal review[] of the 

Products’ . . . .” (citation omitted)); see also J.A. 3874, 

5092. 

After rejecting each of Worlds’s other arguments regarding the DevPub Agreement, the Board concluded that 

“Patent Owner has not demonstrated that the Agreement 

gives Activision any opportunity to control this proceeding.” J.A. 509, 3877, 5094. In so doing, the Board also 

relied on statements in Bungie’s Opposition to Worlds’s 

Motion for Discovery, including that “Bungie is solely 

responsible for the cost and control of the IPRs against 

[Worlds’s] patents,” J.A. 409–10, and that “Activision’s 

payment of development advances to Bungie funded the 

development of the Destiny videogame, not these IPRs,” 

 

12 The parties maintain their respective interpretations of this provision on appeal. 
WORLDS INC. v. BUNGIE, INC. 15

J.A. 416. See J.A. 510, 3877, 5094–95 (relying on these 

statements). In Bungie’s briefing, those statements were 

made without citations to any evidence. See J.A. 409–10, 

416. Nonetheless, from these statements, the Board 

concluded that “Petitioner has expressly denied any 

control or funding of this proceeding by Activision,” and 

“[o]n this record, we accept Petitioner’s express representations that Activision is not controlling or funding this 

proceeding.” J.A. 509–10, 3877, 5094–95. The Board 

ultimately concluded its real-party-in-interest analysis by 

stating that “Patent Owner has not demonstrated that 

Activision is an unnamed real party in interest in this 

proceeding. Accordingly, Patent Owner has not established that the Petition violates 35 U.S.C. § 312(a)(2) or 

that institution of review is barred under 35 U.S.C. 

§ 315(b).” J.A. 511, 3878, 5095. The Board reaffirmed 

this analysis in its final written decisions. J.A. 106–07, 

194–95, 258–59. 

Under the framework we have outlined above, the 

Board was entitled to rely, at least initially, on Bungie’s

list of all real parties in interest, which raised no time-bar 

issues under the facts presented. Here, however, Worlds 

presented evidence sufficient to put Bungie’s identification of itself as the sole real party in interest into dispute. 

Thus, in this circumstance, the Board could no longer 

merely rely upon Bungie’s initial identification of the real 

parties in interest. Instead, the Board was required to

make any factual determinations necessary to evaluate 

whether Bungie had satisfied its burden to demonstrate 

that its petition was not time-barred based on the complaints served upon Activision, the alleged real party in 

interest. 

This marks the point in the analysis at which the 

burden of persuasion becomes essential. There is here a

complete absence of any statement as to which party 

should bear the burden of persuasion. At the same time, 

the Board rejected the patent owner’s arguments because 
16 WORLDS INC. v. BUNGIE, INC. 

the Board was “unpersuaded that there is sufficient 

evidence that Activision is an unnamed real party in 

interest for the reasons given in the Institution Decision.” 

J.A. 107, 195, 259. This implies that the Board assumed 

the burden of persuasion rests with the patent owner. 

Moreover, the Board’s potential reliance on the rebuttable 

presumption from Atlanta Gas Light may have effectively 

skewed the burden of persuasion despite Atlanta Gas 

Light’s statement that it was not approving such a shift. 

Under these circumstances, we cannot discern whether 

the Board placed the burden on Worlds, the patent owner,

to persuade the Board that Bungie failed to list a real 

party in interest that would render the petitions timebarred under § 315(b). As discussed above, this would 

have been improper.

As an aside, we have some concern that the Board 

may have relied on attorney argument as evidence that 

Activision was not controlling or funding these IPRs. See 

J.A. 510, 3877, 5095 (citing Bungie’s briefing and stating 

that “[o]n this record, we accept Petitioner’s express 

representations that Activision is not controlling or funding this proceeding”); see also Icon Health & Fitness, Inc. 

v. Strava, Inc., 849 F.3d 1034, 1043 (Fed. Cir. 2017) 

(“Attorney argument is not evidence.”). This is particularly concerning given that the Board’s apparent reliance on 

such statements seemed to outweigh the actual evidence 

presented by Worlds. Instead of citing evidence to support this factual conclusion, the Board merely cited attorney argument from Bungie’s briefing—attorney argument 

that itself failed to cite evidence, such as affidavits or 

declarations. See J.A. 510, 3877, 5095 (Institution Decisions); J.A. 409–10, 416 (Bungie’s briefing).

In light of these concerns, we find it appropriate to 

remand this case to the Board for further consideration of 

the real-party-in-interest issue. In doing so, we do not 

speak to how the evidence should be weighed, and we do 

not prejudge what conclusion the Board, applying a 
WORLDS INC. v. BUNGIE, INC. 17

proper analysis, may reach as to whether Activision is a 

real party in interest in these proceedings. We note, 

however, that we have issued opinions since the Board 

issued its final written decisions that clarify the meaning 

of the term “real party in interest” in the context of 

§ 315(b). See Applications in Internet Time, LLC v. RPX 

Corp., 897 F.3d 1336, 1351 (Fed. Cir. 2018) (explaining 

that determining whether a party is a real party in interest “demands a flexible approach that takes into account 

both equitable and practical considerations, with an eye 

toward determining whether the non-party is a clear 

beneficiary that has a preexisting, established relationship with the petitioner”); Wi-Fi One, LLC v. Broadcom 

Corp., 887 F.3d 1329, 1336 (Fed. Cir. 2018) (noting that 

the Board, in rendering § 315(b) determinations, “seeks to 

determine whether some party other than the petitioner 

is the ‘party or parties at whose behest the petition has 

been filed’” (citing Office Patent Trial Practice Guide, 77 

Fed. Reg. 48,756, 48,759 (Aug. 14, 2012))). We remand 

with instructions for the Board to weigh the evidence in a 

manner that places the ultimate burden of persuasion on 

Bungie, the IPR petitioner, and to do so in a manner 

consistent with our recent precedent. 

3 

Bungie briefly argues on appeal that, in light of issue 

preclusion principles, Worlds should be estopped from 

contesting the Board’s real-party-in-interest determination. Bungie bases its preclusion argument on the three 

other IPRs that proceeded on a similar time frame as the 

three IPRs now on appeal.13 In those IPRs, Worlds ar-

 

13 The Board issued final written decisions in the 

three IPRs on appeal on November 10, 2016; November 

28, 2016; and December 6, 2016. Meanwhile, the Board 

issued final written decisions in the three unappealed 
18 WORLDS INC. v. BUNGIE, INC. 

gued, as it does here, that Bungie should have named 

Activision as a real party in interest. The Board disagreed. Worlds did not appeal the Board’s final written 

decisions in those IPRs, and the time for appeal has now 

expired. 

The general rule for issue preclusion (also called collateral estoppel) is “[w]hen an issue of fact or law is 

actually litigated and determined by a valid and final 

judgment, and the determination is essential to the 

judgment, the determination is conclusive in a subsequent 

action between the parties, whether on the same or a 

different claim.” B & B Hardware, Inc. v. Hargis Indus., 

Inc., 135 S. Ct. 1293, 1303 (2015) (quoting Restatement 

(Second) of Judgments § 27 (1982)). This general rule is 

“subject to certain well-known exceptions.” Id. (citing 

Restatement (Second) of Judgments § 28 (1982) as listing 

exceptions). 

Bungie devotes just two pages of its briefing to arguing that the basic requirements of issue preclusion are 

satisfied in this case. Appellee’s Br. 62–63. In similarly 

cursory fashion, Worlds’s Reply Brief compiles a handful 

of conclusory assertions in an attempt to avoid issue 

preclusion. Reply Br. 30–32. And because of the timing 

of the six IPRs, the Board did not consider issue preclusion.

In this case, such a limited record is insufficient for 

this court to decide, for the first time on appeal, whether 

issue preclusion should apply to this unusual set of facts. 

The record before us is scant on details regarding the 

issues raised in the three unappealed IPRs. Based on the 

limited record before us, we cannot say that the “issue” is 

the same between the now-final IPRs and the IPRs cur-

 

IPRs on November 28, 2016 (for two proceedings) and 

November 30, 2016.
WORLDS INC. v. BUNGIE, INC. 19

rently on appeal. Bungie, of course, views the “issue” as 

the ultimate determination of whether Activision is a real 

party in interest. See Appellant’s Br. 63. But in our view, 

the determination of whether a party is a real party in 

interest may differ from one IPR to the next, even among 

a set of seemingly related IPRs. Without a more comprehensive understanding of the issues raised in each case, 

we decline to apply collateral estoppel. Instead, given 

that we are already remanding this case with regard to

the merits of the real-party-in-interest analysis, we find it 

appropriate to have the Board analyze in the first instance whether issue preclusion should apply under these 

particular circumstances. In doing so, the Board should 

develop a more complete record that explains the differences, if any, between the issues raised in present IPRs 

and the unappealed IPRs. The Board should also consider 

any relevant exceptions to issue preclusion raised by the 

parties and explain why such exceptions do or do not 

apply to these facts. See Restatement (Second) of Judgments § 28 (1982); see also In re Cygnus Telecomms. 

Tech., LLC, Patent Litig., 536 F.3d 1343, 1349–50 (Fed. 

Cir. 2008) (regarding issue preclusion where a party did 

not appeal all cases consolidated in a multi-district litigation proceeding).

B 

 Because of our conclusions with respect to the realparty-in-interest issue, we need not address the merits of 

the parties’ invalidity arguments at this time. We therefore vacate the Board’s merits decisions in their entirety, 

without speaking to the merits of the Board’s analysis. 

On remand, if the Board determines that the IPRs are not 

time-barred, the Board may use its prior merits analysis

in new final written decisions, and a future panel of the

court will have occasion to review the merits of the 

Board’s analysis at that time, should the parties choose to 

appeal. 
20 WORLDS INC. v. BUNGIE, INC. 

III

For the foregoing reasons, the Board’s final written 

decisions in these three consolidated appeals are vacated. 

On remand, the Board should first address whether 

Worlds is estopped from arguing the real-party-in-interest 

issue. The Board should thoroughly consider the posture 

of the related proceedings, as well as any relevant exceptions to collateral estoppel. If the Board determines that 

collateral estoppel does not apply, the Board should then 

reevaluate the merits of the real-party-in-interest issue. 

And, in light of this court’s recent guidance on the substantive real-party-in-interest inquiry, the Board, in its 

discretion, should consider whether to allow for additional 

discovery on this issue.14

VACATED AND REMANDED

COSTS

The parties shall bear their own costs.

 

14 See Applications in Internet Time, 897 F.3d 1336; 

Wi-Fi One, 887 F.3d 1329; cf. WesternGeco LLC v. ION 

Geophysical Corp., 889 F.3d 1308 (Fed. Cir. 2018).