While in the course of completing the storyline of Grand Theft Auto IV, the player makes a total of ten major choices based on the morality of the player. They are listed below.
"First Date" and "Bleed Out"
- Choosing to date Michelle or rescue Roman first.
- Reward: Nothing for either (Michelle will be concerned on where Niko was if he decided to rescue Roman first, and a small bonus mission gets unlocked of picking Roman up from a hospital if Niko's date with Michelle was first). If Michelle is chosen, Roman's like status will not benefit, and the same effect will occur if Roman is chosen.
- Spare or kill Ivan Bytchkov.
- Spare or kill Cherise Glover.
- Reward: Nothing for kill, appears later as a random character if spared. If she is killed, Dwayne will sympathize, and if she is spared, Dwayne will say that he is relieved, as "she didn't need to die, she's just an idiot". Cherise will reappear soon at the Cluckin' Bell in North Holland as a random character.
- Spare or kill Clarence Little.
- Reward: Nothing for kill. If spared, he appears later as a random character on the north side of the apartment complex where the mission "Holland Nights" takes place, where he is killed by Niko.
- Kill Playboy X or Dwayne Forge.
- Reward: $25,000 for killing Dwayne, or Playboy X's Penthouse, a new set of clothing and Dwayne as a friend for killing Playboy. If Playboy is spared, he will call Niko a "cold hearted killer" for killing Dwayne, claiming he never wants to see him again after Dwayne's death as he was his mentor.
- Kill or spare one of Adam Dimayev's associates.
- Reward: Nothing.
- Kill or spare one of Isaac Roth's associates.
- Reward: Nothing.
- Kill Francis McReary or Derrick McReary.
- Spare or kill Darko Brevic.
- Reward: Nothing. If Darko is killed, Niko later claims he feels "empty" for killing Darko. If Darko is spared, however, Niko will feel better, believing that nothing would change if he killed Darko.
- Choose to strike a deal with Dimitri Rascalov ("If the Price is Right") or exact revenge ("A Dish Served Cold").
- The final three missions of the game are different depending on which ending the player chooses. Both endings will reward Niko with $250,000, though either Kate McReary or Roman Bellic will be killed at Roman's wedding, depending on the player's choice. Choosing "Revenge" will result in the death of Kate and will prompt "Out of Commission", while choosing "Deal" will result in Roman's death and prompt "A Revenger's Tragedy".
The first three, if spared, all become random characters (in Clarence's he appears with a gun and attempts to kill Niko and Niko will have to kill him, it should also be noted that if Niko chooses not to kill him and drive away, Clarence will chase Niko. This contrasts to the other two which will request Niko's help with something). Killing Playboy or Dwayne both offer different rewards, killing Derrick gives Niko money but killing Francis does not give Niko money. The choice of Darko has little to no implication, while the final choice is the biggest of all - it triggers different missions and determines the fate of either Roman Bellic or Kate McReary.