At the conclusion of each mission your ninja techniques are reviewed. Your score and rank will depend on how many enemies you killed and under what circumstances. If you score a high rank your ninja items will be increased. Score the highest rank, Grand Master, and you will be rewarded with a special Grand Master item per mission.
A break down of the scoring system and ranking for Tenchu: Wrath of Heaven when playing with Ayame or Rikimaru is given below. Tesshu’s Ranking System can be found here.
|Undetected Kills||Undetected kills||+ 20||(for each)|
|Detected kills||Detected kills||+ 5||(for each)|
|Spotted||– 30||(for each)|
|Not spotted bonus||+150|
|Innocents||Innocent kills||– 50||(for each)|
|x < 100||3 random ninja items increased|
|100 <||x < 250||5 random ninja items increased|
|250 <||x < 350||8 random ninja items increased|
|350 <||x < 450||all ninja items & 4 random special items increased|
|x > 450||all ninja & special items increased|
The fact that you only need 450pts to gain a Grand Master ranking allows you to deduce two formulae regarding how many times you can be spotted and still gain the highest rank. Suppose a mission has x enemies. Then use these formulae to check how many times you can be spotted, s :
|Formula 1||s <||20x – 150|
|Formula 2||s <||20x – 150|
where Formula 1 calculates s assuming you normally kill any enemy who sees you, and Formula 2 assuming you stealth kill any enemy who spots you. Note these formulae assume you kill every enemy on the level.