Nova is a long-ranged sniper. She excels at taking out strong enemies including bosses, and can easily handle most defensive structures. However, until the mid-late game she is extremely inefficient at handling large groups of weak units like Zerglings and Roaches, and is extremely vulnerable to direct attack.
Nova's buff in 12.5 makes her one of the best hero in the game. Once she has vision with Anvil's Scan ability, she can start bosses by simply marking them. Additionally with Armageddon Mastery her nukes cost significantly less than any other player and she has 99% damage reduction from nukes.
Very early on, often even at level 0, Nova can unlock Heavy Barrel, increasing her range from 5.5 to 7.5, allowing her to outrange Spine Crawlers. This combined with her high base attack damage makes her good at pushing through Zerg structures. However, her base attack speed of 2.5 (improved to 1.95 by the Unobtanium Bolters Talent) makes her extremely inefficient at fending of groups of Roaches. The answer to hordes is Strafe, which gives 4 seconds of 500% increased attack speed, roughly 10 shots, at the cost of 20% attack damage and 50% move speed. However, even this has limited usefulness early on with its base cooldown of 60 seconds. However, with the Havoc Talent and Lightweight Equipment Mastery this can be reduced to 6 seconds, and becomes a vital component of Nova's mid and late-game damage output.
Once learned, Nova has a chance (25%, improvable to 53%) with every basic attack to critically hit, dealing bonus damage. While the bonus from a single crit may seem small, with Headhunter Mastery and Strafe, Nova can deal astounding amounts of damage in short spans of time. Additionally, when fully stacked, Headhunter Mastery causes Nova to recover energy when critical hits are scored, which can overcome Strafe's energy costs to make it infinitely sustainable.
Snipe allows Nova to fire single long-range shots, usually at large enemies, at the cost of energy. With Stay On Target and Lightweight Equipment Mastery, Snipe's initial 20 second cooldown can be reduced to literally 0 seconds, with Ghost Academy Mastery its cast time can be reduced from 1 second to 0.5, and with Marksman Mastery and the Ballistic Scope Talent, its cast (and autocast) range can be extended to an enormous 23. Constant sniping is extremely energy-consuming, but as Snipe does increased damage to Massive enemies on its own, and can be upgraded to deal bonus damage to Psionic and Heroic units, it can be used to very quickly chip away at bosses and Ultralisks.
Combat Drones are small attack craft that float above Nova and fly out to attack her primary target. Initially they have low damage (2 attacks of 10 damage each hit) and a 2-second attack speed, but their damage scales with Nova's level (+0.1 damage per shot per level), and through Drone War and Drone Hangar Mastery their attack speed can be improved to 1 second. Additionally, while initially only one drone can be fielded, Talents and Drone Hangar Mastery can increase this to 4 Drones. All active Drones will target the same enemy if they can. Additionally, as they count as flying units, they can fly up cliffs to engage enemies and provide a small circle of high-ground vision that can be used to attack additional enemies after their original target is destroyed. In the late game, their high attack speed makes them into an effective answer to swarms of weak enemies such as Banelings, and a way of slowly burning down large enemies like Brutalisks while running from them. However, one limit to their utility is that they only pick up targets when Nova is actively autoattacking; repeatedly casting or autocasting Snipe causes them to lose focus and fly back to Nova. (Also, awkwardly, they have a tendency to cause Nova's attack animations to glitch out, making her dance in stead of standing with her rifle shouldered.) Combat Drones are untargetable and immune to all damage, however they will be destroyed if Nova is lifted up from a Hybrid Dominator's Graviton Prison. You will then need to redeploy the Drones manually.
For survivability, Nova has the second lowest base hitpoints of all heroes, second only to Tassadar. However, while Tassadar starts with Shields, Nova does not. The Personal Shields Talent should be taken as soon as possible to make up for this. Additionally, Nova cannot learn Adaptive Armor or most other armor-boosting Talents. To compensate for this, Nova in stead has the Displace ability, making her invulnerable and invisible for a few seconds. It has a long cooldown, but it is an excellent spell for escaping danger, and if used correctly can make Nova extremely difficult to kill. Correct usage of Displace may involve running back towards CP forces or structures, but can also include simply running sideways to escape vision range of incoming EC forces. While this sideways movement may trap you behind enemy lines, it can vastly extend your life expectancy, as if you simply cloak and run towards the CP base, the EC forces chasing you will also be running towards the CP base, and when your cloak runs out they will quite happily kill you.
This mastery increases Life and Energy periodically. It also negates any loss of minerals and XP upon death. It is a good mastery to take for beginners, but it is more limited in modes like FKING INSANE where you only have one life.
This mastery restores some life when it gets low, occurring no more than once every 60 seconds. It also adds an "insane" amount of shields which grants 600 shield points.
Increases energy max by 125 points, increases energy restore rate, and shield restore delay. This is a good mastery to learn when cooldowns are ready long before having enough energy to use them.
This mastery increases snipe damage by 250 points and snipe range by 6. It is a good mastery when enhanced by other snipe talents such as Stay on Target and Ballistic Scope or when used in conjunction with masteries like Lightweight Equipment Mastery, Ghost Academy Training Mastery and Energy Mastery.
This mastery permanently increases your critical hit chance by up to 20%, slowly building in 1% increments. When 20% is reached, critical shots also have a chance to restore 4% of your energy.
This mastery builds up to 100% in 10% increments. Each increment increases Snipe damage by 10, Auto-Attack range by .1, Combat Drone DPS by 1, Critical Hit damage by 4 and Energy max by 5, for a total of 100 Snipe damage, 1 Auto-Attack range, 10 Combat Drone DPS, 40 Critical Hit damage and 50 Energy.
This mastery reduces the cooldown timers of Strafe, Displace and Snipe. When used with talents like Havoc, Wild Ghost Chase or Stay on Target, it is possible to reduce the cooldowns of Strafe to 6 seconds, Displace to 40 seconds and remove the cooldown completely for Snipe, making it very useful.
This mastery increases the radius of your nuke, the damage of it versus heroic and allows you to cast it anywhere on the map that you have vision of. This is a late game mastery, and is mostly used for killing the last few bases at a faster pace, or “cheesing” them by killing the production facilities of the zergs. It’s commonly used for killing the creep towers near the last boss, and is best combined with Radical Restructuring and Massive Blast.