In this case, the chart shows a Scorpio ascendant, aka “Scorpio rising”.
To determine the “chart ruler” or the “ruling planet” check the sign on the ascendant. The planet that rules that sign is your chart ruler.
Aries rising or ascendant = Mars ruled chart
Taurus rising or ascendant = Venus ruled chart
If you don’t know what planet rules what sign you can refresh your memory here: cheat sheet.
Most astrologers feel the ruling planet is enhanced in the chart. Play close attention to the transits both to and from your ruling planet.
For example, if you have a Mars ruled chart, the position of Mars in the sky (and the affairs of the house in your chart where it’s transiting) will be particularly important to you. Same for transits to your natal Mars.
Cancer risings (moon-ruled charts) are sensitive to the moon’s moving through the signs and houses in their chart. This is worth noting. Capricorn risings and Aquarius rising do well to mind Saturn, etc.
When I say, “mind the ruling planet” I mean in every way, shape and form. For example, if the chart ruler is under duress in the chart, this gives information. If the chart ruler is well placed and well-aspected this gives different information.
Familiarize yourself with your ruling planet in front of any other priority you might have, even if you are initially less than interested or affectionate towards the planet and what it represents. This is because to deny the ruling planet and it’s expression is to deny yourself the same.
What planet rules your chart?