Fallout 3 and New Vegas
With Concentrated Fire, your accuracy to hit any body part in V.A.T.S. increases slightly with each subsequent hit on that body part.”— In-game description, Fallout 3
Fallout 3 and Fallout: New Vegas
Every time you target the same body part in V.A.T.S., your chance to hit raises by 5%. For example, if your first chance to hit is 40%, the second will be 45%, the third will be 50%, et cetera. This can lead to very easy head-shots when teamed with other to-hit percent boosters (Sniper, Commando, et cetera). Note that your accuracy can't be higher than 95%.
With the Concentrated Fire perk, every additional attack on the same body part in V.A.T.S. improves your chances of landing a hit.”— Fallout 4 loading screen hints
With the first rank of this perk, every attack on the same body part in V.A.T.S. gains a cumulative 10% bonus to accuracy, and the second rank raises this bonus to 15%. The third and final rank raises the accuracy bonus to 20%, but also increases 20% damage with each attack.
- Unlike other perks that give bonuses to your accuracy in V.A.T.S. (such as Commando, Gunslinger, Sniper) the bonuses gained from Concentrated Fire are additive instead of multiplicative.
- This perk is more effective with weapons that use few Action Points, so that you can fire many times and gain larger bonuses.
- When queuing up shots, it seems to show an increase in each subsequent shot before you even fire, which would mean it ignores whether your shots actually hit and simply gives the accuracy anyway. It is not known how this perk actually functions, but testing does seem to show it to be more powerful than its description.