This article lists the secrets of Metal Gear Solid V: The Phantom Pain.
Save File Bonus
In the aftermath of Missions 3-10, and 12, if the player has both a save file of Metal Gear Solid V: Ground Zeroes, and had managed to extract certain key characters from the Main Mission and Side Ops, the Report screen for recruited soldiers will have a special volunteers banner flash and Miller calling in stating that some soldiers they had earlier extracted in Cuba have decided to rejoin them after hearing that "Big Boss was back."
Destroying the communications equipment prior to starting this mission will cause a stunned Ocelot and Miller to declare the mission complete only seconds after it starts.
Some missions have debriefings that are either unlocked completely or otherwise expanded upon by following certain criteria:
- Mission 7: Either extracting the Red Army brass or otherwise neutralizing them (ie, killing them) only after listening to their speech has Kazuhira Miller relaying to Snake the contents of their meeting.
- Mission 14: Rescuing at least one British POW in addition to the Viscount will have Miller reveal to Venom Snake the Viscount's duplicitous nature and imply that he intends to have the Viscount undergo more severe interrogation for his earlier actions to his comrades before reporting on the delivering of Walker Gears to the various PFs, CFA included.
- Mission 19: If the player either extracts the Major or otherwise neutralizes him after listening in on his conversation with his subordinate, Miller will relay to Venom Snake what the Major revealed on everything he knew about the events, including that ZRS was planning to kill an old man.
- Mission 21: If the player decided to extract the CFA executive instead of killing him, Miller will debrief Venom Snake by revealing that the CFA executive wanted to join Diamond Dogs and reveal that it was his higher-up's idea to prolong the fighting with the implication that he didn't necessarily support it. Similarly, extracting the arms dealer will have Miller reveal that he was headhunted by SANR and that he wasn't actually its president, only receiving his orders from a cutout.
- Mission 22: If the player extracts Mosquito, Miller will reveal Mosquito's past as a former Militaires Sans Frontières member.
- Mission 26: If the player extracts the Trafficker, Ocelot will relay what the trafficker told him about the Devil's House.
Meeting with Eli
When Venom first meets Eli, he'll speak Kikongo during the cutscene if you have an interpreter. If you don't, he'll use English.
Mother Base scenes
A "Happy Birthday" scene can be triggered by returning to Mother Base on your birthday. It changes depending on which characters you have on the Mother Base.
A scene with soldiers fighting each other can be triggered by returning to Mother Base when your GMP is in the red or the morale of your soldiers is low.
Five different scenes can be triggered by returning to Mother Base after going away for 5 real life days. If you don't have DD, a scene with your soldiers will be shown. If DD is still a puppy, a scene with a puppy will be shown. If DD is grown up, one of the three scenes will fully grown DD will be triggered depending on how good your bond with him is.
If Snake does not use a shower in a while, a special cutscene is triggered upon arriving at Mother Base; Pequod, DD and other Diamond Dogs soldiers are seen recoiling from your fly-covered presence, and Ocelot throws a bucket of water at you as punishment. However, if Quiet is present, she will take you to the shower with her. Showering with Quiet is the only bonding moment that can be used with the Medic model.
Shooting the pig's head in Mission 23 will have it oink.
Returning to the ACC while suffering from a serious injury, Venom will be hooked up to an IV drip. If you were seriously injured twice or more, it'll be replaced with a blood transfusion.
As you complete more missions, pictures are added or removed to the interior of the ACC. For example, intel files will be placed on the ceiling, pictures of Quiet are added as your bond grows with her, and as you Fulton extract more soldiers, you'll see pictures of your new army.
When the opportunity to do so arises, shooting Ocelot with tranquilizer darts will make him say humorous lines, such as "Two plus two equals five", "That won't work, I've had drug resistance training" with a slur, the names of Nose Electric Railway train stations (a recurring gag in the series,) and "La Li Lu Le Lo."
Cardboard Box Defense
Using a cardboard box or performing a quick dive will put out fires. Similarly, hiding inside a cardboard box after throwing a stun grenade will have the player avoid the effects of detonation.
Falling Objects Sign
While the Command Platform has less than four platforms there is a sign warning of falling objects near the location that Ocelot teaches the player CQC and fulton game mechanics. If the player stands in front of the sign then in a few seconds a supply box will drop from above, complete with cartoony sound effects. This can only be done once per Mother Base visit or reload.
Using the water pistol on exposed internal components of power or radio equipment will short them out without causing the enemy to suspect an intruder nearby, though they will still come to investigate. It can also be used to destroy mines. Also, using the water pistol on either Quiet or one of the Skulls will have them briefly shake due to the parasites. Furthermore, using the water gun on a guard's face will stun him long enough for the player to take him out before he can raise the alarm. If a water "bullet" hits near a guard it will distract them but if the player shoots while a close guard is looking in their direction then the guard will likely spot them. Like with campfires, the Man on Fire can be neutralized with the water gun, though it will take quite a few shots.
Shooting the AI pod before and after retrieving it will have it spout lines from Metal Gear Solid 3: Snake Eater and Metal Gear Solid: Peace Walker, although the latter will require the player to have glass-piercing ammunition to do so.
When rescuing Miller, you can actually have Venom Snake say "Kept you waiting, huh?" if you press the action button. Also, if the player takes 3 in-game days on the "Phantom Limbs" mission, Miller will be dead when you find him and the cutscene will change accordingly, leading to a Game Over screen.
Throwing a magazine at the soldier's head in reflex mode will have him be stunned instantly, which works even with helmets.
Putting a tranquilized enemy on the bed will make other soldiers ignore him, they will not attempt to wake him up.
Knocking over low-voltage overhead power lines while it is raining will cause it to discharge electricity in the vicinity, which will also shock and instantly stun any soldier in range.
Putting a butterfly on your emblem will stop Quiet from leaving. This way, however, her final missions can't be completed.
Hidden Camouflage Images
When using one of the camouflage patterns for Mother Base, there are images secretly painted in certain areas:
- Base Color 002: A snarling wolf, located near the shower unit.
- Base Color 005: A dog face, near a wall on the Command Platform.
After customizing the ACC with the Splitter camouflage pattern there will be a dog's face, similar to the Diamond Dogs logo, on the port side of the tail boom. The same image can be seen on the back of Venom Snake's right shoulder blade when wearing the Splitter fatigue but for staff members will be enlarged and on their left. The imagery is hinted at in the preview box used when selecting the camouflage or player fatigue to use.
Using the APD camouflage on Mother Base has a hidden cameo of Snake infiltrating Zanzibar Land as well as a Zanzibar Land guard from Metal Gear 2: Solid Snake.