cast and convert for date - effect of sql server settings

1. This works :
select

2010-10-12

2. This doesnt work, because the string format is not compliant with the date format currently used by sql serverselect

Msg 241, Level 16, State 1, Line 1
Conversion failed when converting date and/or time from character string.
3. The following will work : select
2010-10-12 CONVERT(date , cast('10-12-2010' as datetime ) , 102) CONVERT(date , '10-12-2010', 102) CONVERT(date , '2010-10-12' , 102)