The most common and most likely answer to this crossword clue is the 7 plus 8 letter word RUSSIAN ROULETTE
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More clues leading to the result RUSSIAN ROULETTE
- Gamble where the loser has a shot?
- Game whose winner never takes the lead
- Ensures tutorial is a shambles — that's a risky game!
- Aristotle unsure about act of stupid bravado
- Game in which loser first to take lead?
- US literature’s on playing a dangerous game
- Note usual triers messing about – dangerous game
- Challenge ending with death chamber
- Playing at Euros: result in sudden-death shoot-out?
- Rules out nastier play in dangerous game
Buddy explains!

The straight part
We know that "act of stupid bravado" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case act of stupid bravado = russian roulette.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.