Most games assume broad basic competency

You tagged this system agnostic, but it does vary slightly by the system.

To start with, most systems I have used implicitly assume broad basic competency. Most games assume characters can read their native language. Most games in a modern setting assume that a character could drive on a highway under normal conditions without a special skill. While true, highly skilled leadership may be a different story, most characters are assumed to be able to competently organize an already willing group and give basic direction.

In other words, for things that could plausibly be called "basic life skills" appropriate to the setting, most games will encourage you to assume your character could approach it with reasonable competence. This is particularly true of the type of things you normally wouldn't roll for, such as giving basic directions to a subordinate, driving under normal circumstances, reading a native language, basic cleaning and cooking. Depending on the setting, slightly more nuanced things such as finding water and determining whether or not it is safe to drink or making a fire in the wilderness may or may not fall into this category.

Some systems explicitly allow for rolls for skills you don't have.

Above I mostly discussed things that would normally not require a roll. But some systems have explicit rules allowing certain things to be attempted without the relevant skill.

For instance, while basic driving may be assumed, advanced driving of the kind you may need to pursue a fleeing vehicle, escape a chasing vehicle or handle rough terrain may fall under a skill such as drive. But many systems would let someone without specific training roll to attempt one of those actions, though likely at a penalty compared to someone who was trained. What that penalty is would vary by the system.

In the event your system does not have specific rules to address a roll for an untrained skill, I would recommend simply applying your own best judgment as to whether the character should be able to make the attempt. Someone without specific survival training probably could rig up some sort of very basic water filter depending on the setting. Someone without specific leadership training can reasonably make an attempt to persuade, inspire, and organize others, especially if the group is small and already willing. Someone without intensive medical training probably could not perform an appendectomy and any attempt to do so without some sort of medical background should probably fail in a bloody fashion without the benefit of a roll.

Bottom Line

The system you are using may actually cover what to do if someone needs to attempt something they don't have a specific skill for. If it doesn't, then I recommend a middle ground between #1 and #3 on your possibilities.

When the action is something that someone without special training could reasonably attempt, let it roll (either in the sense of just letting it happen or letting them roll to see, depending on how hard it is and whether failure would be interesting). This is both more fun for everyone and more realistic. I attempt things in real life I don't have any training for. Sometimes it works, sometimes it makes things worse, but reality lets me try.

When the action is something that clearly requires significant training to even try, then just say no. I cannot even attempt to perform an appendectomy because I don't even have the background to identify an appendix. I cannot even attempt to read Mandarin because I don't know a single word of Mandarin.

Most games assume broad basic competency

You tagged this system agnostic, but it does vary slightly by the system.

To start with, most systems I have used implicitly assume broad basic competency. Most games assume characters can read their native language. Most games in a modern setting assume that a character could drive on a highway under normal conditions without a special skill. While true, highly skilled leadership may be a different story, most characters are assumed to be able to competently organize an already willing group and give basic direction.

In other words, for things that could plausibly be called "basic life skills" appropriate to the setting, most games will encourage you to assume your character could approach it with reasonable competence. This is particularly true of the type of things you normally wouldn't roll for, such as giving basic directions to a subordinate, driving under normal circumstances, reading a native language, basic cleaning and cooking. Depending on the setting, slightly more nuanced things such as finding water and determining whether or not it is safe to drink or making a fire in the wilderness may or may not fall into this category.

Some systems explicitly allow for rolls for skills you don't have.

Above I mostly discussed things that would normally not require a roll. But some systems have explicit rules allowing certain things to be attempted without the relevant skill.

For instance, while basic driving may be assumed, advanced driving of the kind you may need to pursue a fleeing vehicle, escape a chasing vehicle or handle rough terrain may fall under a skill such as drive. But many systems would let someone without specific training roll to attempt one of those actions, though likely at a penalty compared to someone who was trained. What that penalty is would vary by the system.

In the event your system does not have specific rules to address a roll for an untrained skill, I would recommend simply applying your own best judgment as to whether the character should be able to make the attempt. Someone without specific survival training probably could rig up some sort of very basic water filter depending on the setting. Someone without specific leadership training can reasonably make an attempt to persuade, inspire, and organize others, especially if the group is small and already willing. Someone without intensive medical training probably could not perform an appendectomy and any attempt to do so without some sort of medical background should probably fail in a bloody fashion without the benefit of a roll.

Bottom Line

The system you are using may actually cover what to do if someone needs to attempt something they don't have a specific skill for. If it doesn't, then I recommend a middle ground between #1 and #3 on your possibilities.

When the action is something that someone without special training could reasonably attempt, let it roll (either in the sense of just letting it happen or letting them roll to see, depending on how hard it is and whether failure would be interesting). This is both more fun for everyone and more realistic. I attempt things in real life I don't have any training for. Sometimes it works, sometimes it makes things worse, but reality lets me try.

When the action is something that clearly requires significant training to even try, then just say no. I cannot even attempt to perform an appendectomy because I don't even have the background to identify an appendix. I cannot even attempt to read Mandarin because I don't know a single word of Mandarin.

Most games assume broad basic competency

You tagged this system agnostic, but it does vary slightly by the system.

To start with, most systems I have used implicitly assume broad basic competency. Most games assume characters can read their native language. Most games in a modern setting assume that a character could drive on a highway under normal conditions without a role. While true, highly skilled leadership may be a different story, most characters are assumed to be able to competently organize an already willing group and give basic direction.

In other words, for things that could plausibly be called "basic life skills" appropriate to the setting, most games will encourage you to assume your character could approach it with reasonable competence. This is particularly true of the type of things you normally wouldn't role for, such as giving basic directions to a subordinate, driving under normal circumstances, reading their native language, basic cleaning and cooking. Depending on the setting, slightly more nuanced things such as finding water and determining whether or not it is safe to drink or making a fire in the wilderness may or may not fall into this category.

Some systems explicitly allow for rolls for skills you don't have.

Above I mostly discussed things that would normally not require a roll. But some systems have explicit rules allowing certain things to be attempted without the relevant skill.

For instance, while basic driving may be assumed, advanced driving of the kind you may need to pursue a fleeing vehicle, escape a chasing vehicle or handle rough terrain may fall under a skill such as drive. But many systems would let someone without specific training roll to attempt one of those actions, though likely at a penalty compared to someone who was trained. What that penalty is would vary by the system.

In the event your system does not have specific rules to address a roll for an untrained skill, I would recommend simply applying your own best judgment as to whether they should be able to make the attempt. Someone without specific survival training probably could rig up some sort of very basic water filter depending on the setting. Someone without specific leadership training can reasonably make an attempt to persuade, inspire, and organize others, especially if the group is small and already willing. Someone without intensive medical training probably could not perform and appendectomy and any attempt to do so without some sort of medical background should probably fail in a bloody fashion without the benefit of a roll.

Bottom Line

The system you are using may actually cover what to do if someone needs to attempt something they don't have a specific skill for. If it doesn't, then I recommend a middle ground between #1 and #3 on your possibilities.

When the action is something that someone without special training could reasonably attempt, let it roll (either in the sense of just letting it happen or letting them roll to see, depending on how hard it is and whether failure would be interesting). This is both more fun for everyone and more realistic. I attempt things in real life I don't have any training for. Sometimes it works, sometimes it makes things worse, but reality lets me try.

When the action is something that clearly requires significant training to even try, then just say no. I cannot even attempt to perform and appendectomy because I don't even have the background to identify an appendix. I cannot even attempt to read Mandarin because I don't know a single word of Mandarin.

Most games assume broad basic competency

You tagged this system agnostic, but it does vary slightly by the system.

To start with, most systems I have used implicitly assume broad basic competency. Most games assume characters can read their native language. Most games in a modern setting assume that a character could drive on a highway under normal conditions without a special skill. While true, highly skilled leadership may be a different story, most characters are assumed to be able to competently organize an already willing group and give basic direction.

In other words, for things that could plausibly be called "basic life skills" appropriate to the setting, most games will encourage you to assume your character could approach it with reasonable competence. This is particularly true of the type of things you normally wouldn't roll for, such as giving basic directions to a subordinate, driving under normal circumstances, reading a native language, basic cleaning and cooking. Depending on the setting, slightly more nuanced things such as finding water and determining whether or not it is safe to drink or making a fire in the wilderness may or may not fall into this category.

Some systems explicitly allow for rolls for skills you don't have.

Above I mostly discussed things that would normally not require a roll. But some systems have explicit rules allowing certain things to be attempted without the relevant skill.

For instance, while basic driving may be assumed, advanced driving of the kind you may need to pursue a fleeing vehicle, escape a chasing vehicle or handle rough terrain may fall under a skill such as drive. But many systems would let someone without specific training roll to attempt one of those actions, though likely at a penalty compared to someone who was trained. What that penalty is would vary by the system.

In the event your system does not have specific rules to address a roll for an untrained skill, I would recommend simply applying your own best judgment as to whether the character should be able to make the attempt. Someone without specific survival training probably could rig up some sort of very basic water filter depending on the setting. Someone without specific leadership training can reasonably make an attempt to persuade, inspire, and organize others, especially if the group is small and already willing. Someone without intensive medical training probably could not perform an appendectomy and any attempt to do so without some sort of medical background should probably fail in a bloody fashion without the benefit of a roll.

Bottom Line

The system you are using may actually cover what to do if someone needs to attempt something they don't have a specific skill for. If it doesn't, then I recommend a middle ground between #1 and #3 on your possibilities.

When the action is something that someone without special training could reasonably attempt, let it roll (either in the sense of just letting it happen or letting them roll to see, depending on how hard it is and whether failure would be interesting). This is both more fun for everyone and more realistic. I attempt things in real life I don't have any training for. Sometimes it works, sometimes it makes things worse, but reality lets me try.

When the action is something that clearly requires significant training to even try, then just say no. I cannot even attempt to perform an appendectomy because I don't even have the background to identify an appendix. I cannot even attempt to read Mandarin because I don't know a single word of Mandarin.