What happens if i kill a Bandit that has surrendered?

[Læms]

because i killed one by accident when i was in a fire fight with the rest of the bandits, will this change the outcome of the game?

[Jig McGalliger]

I believe this counts as a negative moral point. If it only happens once or twice, i doubt it will change the outcome of that level.

[Lithurge]

It might tip it over the edge if you do lots of other things wrong and skip doing side quests for other characters, but if it's the only bad thing you've done then no it won't affect the ending.

[Purity+Control<]

finished the game 5 times, nothing happens, you can kill them freely. The only bandit that gives you negative karma are Saul (the guy you take the key for the car from in the beginning of caspian) and the tied up bandit that gets killed by the wolf if you don't free him first.