The national dressage levels as sanctioned by the US Dressage Federation are:
Introductory, First, Second, Third, Fourth (other countries have their own levels)
The international levels sanctioned by the FEI are:
Prix St. Georges, Intermediare I, Intermediare II, Grand Prix (Olympic)
Within each level there are 2-4 tests to choose from. In theory the first test is the easiest while the fourth is the hardest, but this is not always the case. You can chose to skip tests. For example you could select Training Level 2 and Training Level 4. You may ride the same test more than once (but in different shows). Tests are rewritten approximately every 4 years.
What to expect in the lower levels:
Intro - Ridden at walk and trot only, no canter. Movements include free walk, medium walk, rising trot, and 20 meter circles. The horse and rider are off to a good start, showing acceptance of the aids, relaxation, and beginning to develop bend.
Training - Canter and sitting trot are introduced. New movements include 20 meter canter circles, stretching at the trot, and changing bend at the trot. The horse is developing more bend, and accepting contact with the bit.
First - Lengthening trot and canter are introduced, as are 10m and 15m circles, serpentines, leg-yield, and change of canter lead through trot. The horse is developing impulsion and balance.
Schooling versus Sanctioned
In a nutshell a "schooling" show is "off the record"; scores are not reported to the governing body (USDF). Scores from a "sanctioned" show are. Schooling shows are less expensive and typically less formal. However both schooling and sanctioned shows are judged the same way.
Note about Eventing
This article only discusses dressage alone. Dressage as part of eventing is judged according to the same principles as dressage alone. However the levels and the scores are different. In the US, tests are governed by the US Eventing Association.
Each movement is scored:
10 – excellent
9 – very good
8 – good
7 – fairly good
6 – satisfactory
5 – sufficient
4 – insufficient
3 – fairly bad
2 – bad
1 – very bad
0 – not execute
As defined by the test, the score for some movements will be multiplied by a coefficient. This implies the movement is particularly important.
At the bottom of the score sheet are the collective marks for the entire test. Each of these is multiplied by a coefficient.
1. quality of gaits
4. position and effectiveness of the rider (that's the only score for just the rider)
Finally, the scores from the entire test will be added together and divided by the highest possible score, giving the final percentage.
What the numbers really mean
In practice, scores tend to be clustered in the middle of the scale. A "5" is a passing grade; the movement was performed, but it was slightly flawed or not overwhelmingly impressive. Think "so-so" or "just OK". "6" is a bit above average and "7" is rather good. "8" and above are very good, with "9" and "10" being extremely rare scores. A "4" means "needs improvement" and below 4 typically indicates something went wrong. A low score means you should practice that movement more. But if something unexpected went wrong, do not be discouraged.
Next to each movement, you may find notes. These were written by the scribe (often in short-hand) as the judge spoke them. There may be overall comments at the bottom of the test. Often the comments reveal more than the scores. Pay particular attention to similar comments that you receive from multiple judges.
If you are scoring mostly 5s, with some scores higher or lower, you are showing at the correct level. If you are scoring mostly 6s, with frequent 7s or higher, you should consider moving up a level. If you are consistently scoring higher than that, you are more than ready to move up a level for a new challenge. You know yourself and your horse. Most horses are capable of moving up through the low levels; Intro through 1st. Breeding, and conformation are not particularly important at those levels. Many experienced dressage people can tell you stories of unlikely equines (I've read about mules!) being successful at low levels. The bond you share and learning together as a team will lead you to success in the lower levels.
Interpreting test scores: Example
This example is a scored dressage test, Introductory Level - Test A 2007. The test was performed in June 2008 at the CVDA Summer Schooling Show before a licensed L level judge. The final score was 125 points out of 200 possible for 62.5%. I was the rider, an adult re-starting after riding 4-H in my youth. The horse was my boy Armani, coming 6 at the time Morgan/Trakehner gelding. This test features a range of scores, shows the importance of coefficients, and the comments paint a picture.
The overall picture in this test, is a horse and rider who are off to a good start but need improvement in a few specific areas: relaxation and flexion, and acceptance of the aids. Note that most of the judge's comments reflect this. Movement 6, the free walk, is worth noting. The horse scored well here, 8, and this movement was multiplied by a coefficient of 2. However, also note that the judge commented "could use more energy", which kept the walk from being better. Also note that the horse scored 5 on both halts. The judge commented that he "wiggled" into the halt and "walked at K" in the second halt. The "walk at K" was too early. The trot-walk-halt transition was supposed to be performed closer to X.
In the collective marks, the judge circled "relaxation of the back" and "acceptance of the aids", noting that those areas need improvement. Also in her final comments, she said "work on stretching head and neck down into consistent connection". That confirms the overall picture. I can tell you that the judges comments were very accurate. They reflect what we'd been hearing consistently from our instructor in lessons.