Optional Fates are events that players can do to determine how they want the characters in a storyline or a mission to turn out. Essentially, It allows the player to decide the fate of the character(s) or mission(s).
Mechwarrior 2: MercenariesEdit
Dust River - During the Gravenhage Campaign, if the player chooses to inspect the Enemy DL Catapult, then the mech will turn on its allies and fight for you.
Judas Kiss' - At the conclusion of the Last Frontier Campaign, which sees the player capture a Clan Kodiak assault 'Mech for the Draconis Combine, the player has the choice of handing over the powerful 'Mech to his employers as planned or destroying the Combine forces to save the prize for themselves.
Dread Legion - In the mission Blood Cauldron, the player will receive a bribe from the Mercenary unit. If the player accepts the bribe, they will attack their employer and walk off with 4 million c-bills. However this decision will prevent the player from taking any DC contracts until the Wolcott campaign. Should the player refuse the bribe, they will walk off with 2 million C-bills and Star League technology.
Mechwarrior 4: VengeanceEdit
Evanda Castro - Towards the end of the story, Karl and Elise urge Ian to either save his sister or go after the armory respectively. Should the player decide to do the former, then Castro will remain on Kentares untouched. Should the player go after the armory, then they would face Castro and her forces, killing her and taking her mech in the process.
Damon Squire - If the player decides to go after the armory, Elise will tell Ian that Damon went AWOL going after his sister. Successfully taking the armory will prompt Elise to tell Ian that no one from Joanna's unit survived. This would likely presume Damon Squire to be among them as he does not appear in the last mission Endgame. The player will also recover a Daishi from this choice. However if the player chooses to rescue Joanna, he will appear in a Mad Cat as an ally than a lancemate. Damon will join the player in the final mission upon rescuing the player’s sister.
Mechwarrior 4: Black KnightEdit
Kentares Free Army - During the Kentares Campaign, Eric McClair has the option to assist the rebels. Should the he assist the rebels throughout the game, then they will become allies. If the player decides not to help the KFA throughout the game, then they will become enemies to the player. It will even skip killing Ian as a result.
Mechwarrior 4: MercenaresEdit
Hammer and his lance - In the mission, "Styk - Reinforcements", the player is given the option to save Hammer Lance of Lindon's Battalion. If the player arrives too late or deliberately refuses, Hammer Lance will be destroyed and not appear for the next mission. Should the player make it in time to save Hammer Lance, they will assist the player in ”Styk - Evacuation”.
Aisa Thastus - If the player chooses the infamous decision to backstab Clan Jade Falcon in the mission "New Exford - Backstab", the player will have to fight Star Colonel Aisha Thastus, killing her in battle. Should the player take the noble route and undergo the mission "New Exford - Beach Fight", they will face her in honorable combat and claim her as a bondswoman for the rest of the game, under the nickname "Falcon".
Lt. Dunman - During a raid on Halloran V, Spectre will run into the mercenary unit, Burr's Black Cobras. Lt.Dunman will warn the player’s mercenary unit to surrender. Upon completing the objectives, Dunman will tell his Lance to disengage. If the player lets his lance leave, then the Black Cobras will not hold a grudge towards Spectre. Should the player destroy Dunman’s lance, they will salvage the remaining mechs. The Cobras will later declare their vendetta on Spectre. Oddly enough, Lt. Dunman's name never appears on any of the mechs, however the game implies that he is either dead or alive depending on the fate of the lancemates.
Lt. Cho - On New Canton’s campaign conclusion, Lieutenant Cho will take the rest of the Harloc Raiders to retreat. If the player holds their fire, the remaining Raiders will leave the field. Should the player fire at the retreating foes, then the Capellan units will return fire. Just like Lt. Dunman, Cho's name never appears on any of the mechs.