I’m a big fan of starting with fairly sketchy characters (and world) and letting them develop in actual play. Sometimes it works well, sometimes less so. There is one phenomenon that causes a sort of disconnect. The phenomenon is that of pulling out skills or equipment out of thin air or non-defined backgrounds, and doing this exactly when having that skill would be convenient.
To clarify, the problem is not that this is abusive or makes challenges too easy. If merely having a skill is sufficient to make a challenge null, it was poorly designed to start with. Abusive use is likewise a nonproblem.
The problem is that it strains credibility it feels abusive, even when it is not. As a friend said, a set of lockpicks will not simply materialise out of nothing. Still, this sort of thing seemingly happens all the time in whatever media one prefers to consume.
So, a potential solution I’ll be experimenting with: Equipment and skills and so one must be foreshadowed in a different scene before they can be brought to play. This may be the character telling about some related events, or buying equipment (naturally), or player narrating that the character is oiling the daggers he usually keeps hidden.
As a bonus, if there’s a gun in the first scene, someone might very well use it later. Chekov is not assured to be happy, but some movement towards that direction is achieved, I reckon.