Last Man Standing
First Flight #45
Beginner FriendlyFoundrySolidity
100 EXP
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Submission Details
Severity: medium
Valid

[H-1] Throne Cannot Be Claimed — Game Is Permanently Bricked

wolf_kalp

Root + Impact

[H-1] Throne Cannot Be Claimed — Game Is Permanently Bricked

Description

The claimThrone() function contains a faulty require statement that prevents any user from ever claiming the throne.

Specifically, it checks:

require(msg.sender == currentKing, "Game: You are already the king. No need to re-claim.");

This condition only allows the current king to call claimThrone(), which completely contradicts the purpose of the game — where new players are supposed to outbid the current king to claim the throne.

At deployment:

currentKing == address(0)

First caller (e.g., Bob) will never be address(0)

⇒ claimThrone() always reverts

⇒ No one can ever claim the throne

Impact:

1.Critical game-breaking flaw

2.No one can ever become King

3.All ETH sent is wasted or locked

4.Prize pool never accumulates

5.Game logic never progresses

6.Contract is permanently bricked

Proof of Concept

​
// assume: initial claim fee = 1 ETH, currentKing == address(0)
​
claimThrone() called by Bob (EOA != address(0)):
​
→ require(msg.sender == currentKing) fails
→ reverts: "Game: You are already the king."
→ Bob cannot claim throne
→ No state updates
→ Game cannot begin
​
// Game is now in a permanently unusable state
​

Recommended Mitigation

  1. Correct the require logic:

Replace:

require(msg.sender == currentKing, "Game: You are already the king.");

With:

require(msg.sender != currentKing, "Game: You are already the king.");
​
Updates

Appeal created

inallhonesty Lead Judge about 2 months ago
Submission Judgement Published
Validated
Assigned finding tags:

Game::claimThrone `msg.sender == currentKing` check is busted

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