Their are several ways to get RARE engrams; beginners can get them from doing missions on Earth, The Moon, Mars, and Venus, but more likely than not, the rare emblems don't appear. So here are a few ways that guarantees rare emblems and maybe even legendary emblems, too.
- Do a strike, preferably Vanguard Wolf or Vanguard Tiger, but the other strikes should work, too.
- Participate in weekly and daily heroic strikes, those give you a lot of rare engrams and you get one as a reward after completing the weekly heroic strike.
- Track down fallen wolves in Earth, the Moon, Mars, and Venus and kill them. After you beat them you will get an ether key and if you can find the chest in time, you will usually be rewarded a couple of rare engrams along with a bunch of planetary material
- level up your crypt arch, when you do, you will get a package from the postmaster that comes with rare and legendary engrams.
This process could take awhile, but you will soon get several rare engrams and if you can level up your crypt arch high enough, then those blue engrams will turn into legendary armor, weapons, or materials.