With Intravenous 3, we continue to work on and polish the little things that made the previous two games fun. In Intravenous 1, enemies would react to noise made by the player instantly.
This made certain elements of stealth rather annoying - the player would be punished for making the slightest mistake with an instant reaction.
One of the improvements IV2 brought over IV1 were timed reactions to noise - the reaction depended on the type of noise and distance to the NPC.
No longer were you punished with an instant reaction to noise the moment you made even the slightest bit of movement noise that just happened to be close enough to an enemy.
Intravenous 3 expands on this - now, the time it takes for an NPC to react to noise made by the player depends on three more factors:
the radius of the noise - the quieter the noise is, the slower enemies react to it
enemy alertness state - relaxed enemies react slowly, but suspicious or alert enemies react quicker. Combat is where reactions are as fast as they are in Intravenous
enemy stress level - an enemy may be alert, but not stressed - every time the player makes noise that is heard, or is seen, it increases an enemy's stress level - this is a system that was present since IV1, but has now been plugged into the noise reaction time. Given a high enough stress level, this can completely outweigh the other two parameters.
These three new parameters mean that the player has a greater time window to finish any maneuver that would alert enemies. It is the type of behavior that makes sense - you wouldn't expect a relaxed person to react to the sound of a soft footstep as fast as someone who is in active combat.
Lastly, yet another common criticism of Intravenous 1 & 2 was that should the player make enough noise, enemies knew exactly where it came from, regardless of how far away it was - this was mostly applicable to gunfire.
And it is an absolutely valid point - it makes no sense for enemies to know exactly where the player is, if he shot a weapon indoors, while being far away from an enemy.
That is why for Intravenous 3, loud, far noise (or if it's obscured by many walls) will still alert enemies, however they will not know the exact location.
They will know the general area where the noise came from, but not the exact position, granting the player even more leeway when it comes to escaping enemies or otherwise using loud noises to their advantage - or the exact opposite, spreading enemies out, creating a more difficult situation than in previous games.
You might think that these are minor changes, but for stealth players they are important, and the entirety of Intravenous games is filled with these little details that, when isolated, seem like nothing special at all.
It is when they're put together, that the jigsaw puzzle, where each little piece plays into the big picture, presents itself and has a massive effect on every single part it's connected to - that has always been the design philosophy of the Intravenous games and it continues so with the third installment.
Thank you for reading today's devlog, and stay tuned for the next one!