As the first set of a new series, all Pokémon Ga-Olé machines upgraded to run Ultra Legend feature updated graphics on the user interface and have the facility to produce and dispense disks featuring the updated Ultra Legend layout. The series also begins a new numbering system, with sets prefixed with a "UL" and the set number starting at 1.
No significant gameplay mechanics were introduced in this set; the Dash System remains the primary method of interaction during Get by Battle mode. The main focus of the Ultra Legend series, however, is the Ultra Beasts. Both Poipole and Naganadel have previously featured in Pokémon Ga-Olé following their debut in Pokémon Ultra Sun and Ultra Moon but the Ultra Legend series begins to showcase them in earnest. The first set includes powerful Grade 5 versions of the Parasite Pokémon Nihilego and the Swollen Pokémon Buzzwole. Ultra Beasts could be encountered on any course that featured an Ultra Beast Appears! (Japanese: ウルトラビースト あらわる！) icon within a limited timeframe. Nihilego could be encountered from the launch of the set until August 8, 2018, while Buzzwole could be encountered from August 9 until September 12, 2018. Ultra Beasts have the same encounter rate as Grade 5 Pokémon and will appear silhouetted in a short sequence before being introduced, similar in fashion to regular Grade 5 Pokémon, albeit with an Ultra Wormhole backdrop. Players in battle with an Ultra Beast during Get Time! will activate Beast Ball Chance! (Japanese: ウルトラボールチャンス！Ultra Ball Chance!), which appends a Beast Ball to 3 slots on the roulette (1 Poké Ball, 1 Great Ball, and 1 Ultra Ball). Selecting one of these slots will throw a Beast Ball at the Ultra Beast, which has a greater chance of capturing it compared to other Poké Balls (except the Master Ball).
In addition to the Ultra Beasts, many other Pokémon could be encountered and caught as part of the set. The evolutionary families of the Generation VIIstarter Pokémon were available for the third time, whist those of the Generation II starters had their Pokémon Ga-Olé debut. Legendary duoLugia and Ho-Oh return as Grade 5 Pokémon in this set with access to Z-Moves and could be encountered on one of the launch courses. Later courses featured the Legendary Order Pokémon Zygarde, available in all three of its Formes, and the Legendary Eon Pokémon Latias and Latios. The Mythical Time Travel Pokémon Celebi was later added to the roster of Pokémon that could be encountered on the Lugia launch course. New versions of the two Cosmog originally from the second Dash set could be encountered in the Let's Begin Ga-Olé! Course. While identical in terms of stats, they differ by featuring the Ultra Legend series graphical layout and a hollow star next to their original collection number. If evolved into Cosmoem and Grade 4 Solgaleo or Lunala, these disks also feature the Ultra Legend series graphical layout. The Grade 5 versions are no different to their Dash series counterparts.
Trainer and Battle Mode was available to challenge from August 16, 2018 and provided 5 new opponents for players to battle. The Trainers included 2 new classes and a new Battle Leader, Emako, who could not be challenged until the other 4 Trainers had been defeated. Promotional Latias or Latios disks could be dispensed for an additional ¥100 following a battle with Emako, with 'WINNER' versions available to those who successfully defeated her team.
Mimikyu, Golisopod, and Hydreigon were added as Support Pokémon from this set. Players registering a Ga-Olé Pass for the first time would automatically receive Mimikyu as a Support Pokémon as part of the Pokémon Ga-Olé Welcome Campaign.
Its Z-Move!! Lugia Course
Playable at set launch
Necrozma Again Course
Playable at set launch
Let's Begin Ga-Olé! Course
Playable at set launch
Power Up! Zygarde Course
Playable from July 19, 2018
Latias & Latios Course
Playable from August 2, 2018
Powerful Pokémon One After Another Course
Playable from August 30, 2018
Available at participating stores as part of the Black Mega Gardevoir Campaign, which ran from June 17 until July 8, 2016
Only Eevee Course
Playable from July 5 to September 12, 2018 at all Pokémon Centers and Pokémon Stores
Available in Happy Meals at participating McDonald's restaurants on July 7 and 8, 2018
Special Lugia Course
Playable from July 7 to September 12, 2018
Available as an insert in issue 59 of Pokémon Fan, released on July 13, 2018
Greninja Again Course
Playable from July 13 to September 12, 2018
Special Power Up! Zygarde Course
Playable from August 16 to September 12, 2018 on select units