The service charge added to the bill doesn't go to the staff. You need to leave a separate tip if you want them to get something (and give it to them directly if you really want to make sure they get it).
Regarding Amoud's statement that "Standard tipping percentage in the West is 15%, and it is actually considered in bad taste if you tip less."
This isn't true for the entire West.
In the UK tipping is still considered discretionary - i.e. you tip if you think they deserve it (which is how it should be in my opinion), and it's usually 10% (or whatever you feel they deserve).
I know however that in the US waiting staff rely on tips to make up their poor salary, so there it is considered rude not to tip.
The service charge added to the bill doesn't go to the staff. You need to leave a separate tip if you want them to get something (and give it to them directly if you really want to make sure they get it).
Regarding Amoud's statement that "Standard tipping percentage in the West is 15%, and it is actually considered in bad taste if you tip less."
This isn't true for the entire West.
In the UK tipping is still considered discretionary - i.e. you tip if you think they deserve it (which is how it should be in my opinion), and it's usually 10% (or whatever you feel they deserve).
I know however that in the US waiting staff rely on tips to make up their poor salary, so there it is considered rude not to tip.