Bound by fate
Whether you succeed or fail, your results are bound by fate. You cannot retry the same test unless the circumstances significantly change. If you fail to pick a lock, that lock is beyond your adventurer’s abilities. If you fail to climb a wall, that wall is unclimbable.
But maybe the warrior in the company can bash down the door. And maybe the sorcerer has a magical cloak that allows you to fly over the wall. You’ll have to find another way past an obstacle if you fail in the test.
You can also attempt a test again if the circumstances significantly change. Significant change usually means new ideas, new tools, or a new twist on an old situation.
Because His Majesty the Worm is a fundamentally collaborative game, fellow guild members are also bound by fate. If one person attempts something and fails, it’s established that it cannot feasibly be done at present. No fair having each guild member try successively until somebody succeeds. However, additional guild members can attempt alternate methods to bypass the obstacle.
It’s important to note the GM is also bound by fate. The GM may not call for multiple frivolous tests to see if an adventurer can accomplish a single task. The more times a successful test is reattempted, the more chances the player has to fail. The GM may only call for repeated tests when the situation meaningfully changes.