The Double IS route, or the IBBFAF route, is the current fastest known real time-viable Any% route for Metroid Prime. This route has the unusual distinction of being both the fastest route and the "beginners route" due to its modularity; players can skip some or all of the difficult tricks in the route without changing its structure. The vast majority of current players, no matter their skill, use this route.
The fastest single-segment time anyone has achieved with this route is T3's 0:49, which is the current world record.
Additionally T3's run also broke the Frigate Escape record with a time of 5:35:35.
The route is named as such because it requires players to perform the infinite speed (IS) glitch twice: once to get the Artifact of Sun, and again to get the Power Bomb Expansion in Magma Pool. It is sometimes jokingly known as the IBBFAF route due to the fact that players perform the Ice Beam Before Flaahgra (IBBF) wallcrawl after Flaahgra (AF).
This route is convenient in that it allows players to add or remove difficult tricks without changing the rest of the route. There are four main options from which players can choose.
- Get Wave Beam in-bounds and do Sun IS to get the Artifact of Sun; replaces Wave/Sun IS.
- Do the puzzle in Energy Core and do far Chozo Ruins in-bounds; replaces IBBFAF.
- Fight Thardus to get the Spider Ball; replaces Spiderless Shafts.
- Get the Artifact of Newborn after obtaining the Phazon Suit; replaces Early Newborn.
- Fight Metroid Prime Exo; replaces Exo Skip Wallcrawl.
It is commonly suggested that the harder tricks should be added back into the route in order of increasing difficulty and increasing time savings. This leads to the suggestion that players learn and incorporate the tricks in this order: Spiderless Shafts --> Wave/Sun IS --> IBBFAF --> Exo Skip <--> Early Newborn.
|1||Space Jump Boots||Tallon Overworld||Alcove|
|2||Missile Expansion||Chozo Ruins||Main Plaza||halfpipe|
|3||Energy Tank||Chozo Ruins||Main Plaza|
|4||Morph Ball||Chozo Ruins||Ruined Shrine|
|5||Missile Expansion||Chozo Ruins||Watery Hall Access|
|6||Charge Beam||Chozo Ruins||Watery Hall|
|7||Morph Ball Bomb||Chozo Ruins||Burn Dome|
|Missile Expansion||Chozo Ruins||Gathering Hall||optional|
|8||Varia Suit||Chozo Ruins||Sunchamber|
|9||Artifact of Wild (1)||Chozo Ruins||Sunchamber||Early Wild|
|10||Artifact of Nature (2)||Magmoor Caverns||Lava Lake|
|Energy Tank||Magmoor Caverns||Transport Tunnel A||optional|
|11||Boost Ball||Phendrana Drifts||Phendrana Canyon|
|12||Wave Beam||Phendrana Drifts||Chapel of the Elders||optional Wave/Sun IS|
|13||Artifact of Sun (3)||Phendrana Drifts||Chozo Ice Temple||optional Wave/Sun IS;
otherwise Sun IS
|14||Artifact of Strength (4)||Magmoor Caverns||Warrior Shrine|
|Missile Expansion||Chozo Ruins||Ruined Shrine||optional; halfpipe|
|15||Artifact of Lifegiver (5)||Chozo Ruins||Tower Chamber|
|16||Power Bomb Expansion||Chozo Ruins||Magma Pool||Magma Pool IS|
|17||Ice Beam||Chozo Ruins||Antechamber||optional IBBFAF|
|18||Missile Expansion||Tallon Overworld||Life Grove Tunnel|
|19||X-Ray Visor||Tallon Overworld||Life Grove|
|20||Artifact of Chozo (6)||Tallon Overworld||Life Grove|
|21||Missile Expansion||Tallon Overworld||Overgrown Cavern||via Reflecting Pool|
|22||Missile Expansion||Tallon Overworld||Transport Tunnel B|
|23||Plasma Beam||Magmoor Caverns||Plasma Processing|
|24||Artifact of Spirit (7)||Phendrana Drifts||Storage Cave|
|Power Bomb Expansion||Phendrana Drifts||Security Cave||optional|
|25||Artifact of Elder (8)||Phendrana Drifts||Control Tower|
|Energy Tank||Phendrana Drifts||Research Lab Aether||optional|
|26||Thermal Visor||Phendrana Drifts||Research Core|
|27||Energy Tank||Phendrana Drifts||Transport Access|
|Spider Ball||Phendrana Drifts||Quarantine Cave||optional|
|28||Power Bomb||Phazon Mines||Central Dynamo||via Magmoor Workstation|
|29||Artifact of Newborn (9)||Phazon Mines||Phazon Mining Tunnel||optional Early Newborn;
otherwise after Phazon Suit
|30||Phazon Suit||Phazon Mines||Elite Quarters|
|31||Energy Tank||Phazon Mines||Processing Center Access|
|32||Artifact of Warrior (10)||Phazon Mines||Elite Research|
|33||Artifact of World (11)||Chozo Ruins||Elder Chamber||via Great Tree Hall|
|34||Artifact of Truth (12)||Tallon Overworld||Artifact Temple|
- Grapple Beam
- Gravity Suit
- Spider Ball (optional)
- Super Missile