To become King of England in Bitlife, you must either be born as the son of the King of England or as a prince in the royal family. You can also marry into the royal family by dating a royal via the dating app under the love activity tab in the game.
However, both being born as a royal and marrying into the family requires a bit of luck. The chance of it happening can be increased if you choose the United Kingdom as your birth location.
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You can also try rerolling characters until you get one born as a prince of the English Royal family or a member of the royal family. If you are lucky for this to happen, then you will need to wait for the current King to die to become King of England.
For the marriage option, you will need to keep finding dates until you find one that is a princess or a member of the royal family. If you manage to find a royal to marry, you can then attempt to become King by outliving all other royals or murdering your way to the throne.
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