As you may have guessed, the definitive answer is it depends.
Most treatments of this topic conclude that Flurry has the highest Damage output, but oversimplify this question to arrive at the conclusion, even otherwise-great guides. Usually, the guides fail to accommodate for To-Hit chance, Critical Hits, or even variable effects (e.g. the answer may differ between high-Strength characters and high-Dexterity characters).
Additionally, Star Wars: Knights of the Old Republic 2 altered both Flurry and Power Attack from KotOR, and with their tweaks, pleasantly surprised me with the balance across a myriad of parameters.
Variables that affect the Damage-per-Round calculation:
- In conjunction with Target's Defense
- And again, for Two-Weapon fighting, the Attack values for each hand will probably differ.
- Number of Attacks per Round
- An Off-Hand weapon adds one Attack with that weapon per Round. Any additional Attacks (from Master Speed or the Juyo Form) will add Attacks only from the Main Hand Weapon.
- Critical Threat Range
- A Critical Hit roll does not always produce a Critical Hit; it only gives the opportunity for an additional Attack Roll. If the Attack Roll Hits, then apply the Critical Damage.
- Critical Multiplier
- Critical Hit Attack Modifier
- Only from the Juyo Lightsaber Form
- See the above Critical Threat explanation; this Modifier only applies for the Attack Roll after the Critical Threat Roll.
- Massive Criticals (bonus Damage on a Critical Hit)
- Target's Damage Reduction
- You can almost calculate the output Damage with a simple formula, until you account for Damage Reduction (because Reduction greater than Damage will produce 0 Damage, not a negative value); with Damage Reduction, you have to perform binomial coefficient expansion.
To assist in these calculations, I actually created a spreadsheet with a macro (custom script) for Neverwinter Nights, which uses the same base combat system as the KotOR games. To adjust for KotOR, you can enter a Lightsaber as a weapon with
2D8 for Damage (or
2D10 for a Dual-Bladed Saber, or
2D6 for a Short Saber). The sheet only calculates for a single Attack, so you'd have to create additional columns to multiply by the number of Attacks per Round, and don't forget to input a different row for your Off-Hand weapon and add that total to your Main Hand weapon when calculating for Two-Weapon Fighting. Also, the spreadsheet does not account for the Critical Hit Attack Modifier from the Juyo Form.
A couple of interesting outcomes and takeaways:
- You will increase your damage the most with significant changes to small values; changing already-large values will yield with diminishing returns.
- For example, increasing the Critical Hit Multiplier with the Shien Form will have a greater value for a Critical Strike Attack (x2 to x3, +50%) than a Power Attack (x3 to x4, +33%), and adding attacks with the Juyo Form with have less impact on a Flurry Round (4 Attacks to 5) than another Attack type (3 Attacks to 4).
- For Lightsabers (not Dual-Bladed), the Keen Property can increase Damage much more than a simple Damage bonus for Flurry and Power Attacks.
- Additionally, against enemies with high Defense, Attack bonuses will have a significantly greater impact than Damage bonuses. Don't underestimate the value of the Attack bonus of Dueling, especially without access to the Superior Two-Weapon Fighting Feats (which only a Jedi Weapon Master or Sith Marauder can choose). In many cases, the Damage output from Dueling will beat the Damage output of either Dual Sabers or a Double-Bladed Lightsaber.
- Power Attack's Damage bonus diminishes in value as other Damage Bonuses enhanced the weapon, obsoleting the Attack Type for the endgame of KotOR. But, with KotOR2's addition of the Critical Multiplier bonus, Power Attack holds its value throughout the game, especially with a weapon which has the Keen property.
- Finally, for extreme values (e.g. 95% Hit chance, +99 to Damage), I think the Dual-Saber Critical Strike eventually wins, but this only provides fodder for victory in Internet arguments, rather than value in-game.