Hacking (DXHR)

Unlike other games in the Deus Ex series, in Deus Ex: Human Revolution, hacking has become a minigame. While keypad codes and computer passwords are often obtainable, there are many instances in which hacking is required to progress through the game (unlike the persuasion minigame, which can almost always be bypassed through the use of alternative tactics).

Overview
Jensen can hack security terminals and computers throughout the course of the game. This allows him to open security doors, disable or reprogram cameras, turrets, and robots, gain extra credits, experience, and nuke/stop virus software, and view emails that can provide him with access codes and item locations (as well as storyline information).

This is accomplished with a minigame where the player needs to capture a critical or security node, by moving from node to node, capturing along the way. Capturing nodes however, will alert the enemy security, which will also begin capturing nodes, attempting to reverse-trace Jensen. If Jensen's starting node is captured, the terminal will lock him out, and possibly sound an alarm, alerting enemies in the area to Jensen's location.

Detailed
The goal of the minigame is to hack either the critical nodes, represented by the green balls, or the enemy's security node, represented by the red tower. However, the security node will not be able to be captured all the time. Often there will also be more than one critical node - all critical nodes on a system must be captured to fully hack the system. Once Jensen has been detected however, it becomes a race against time as the enemy security system will begin tracing Jensen, capturing nodes starting from the security node. Each captured node will become fortified, making it much harder for Jensen to hack them.

As Jensen can only hack nodes that are adjacent to already captured nodes, the player must move from node to node, advancing from the starting location to all critical nodes on the map. Hacking each node however, has a chance of alerting the enemy security, which will start the timer before Jensen is detected and locked out. This chance can be lowered with the Hacking: Stealth augmentation. Jensen can increase the amount of time he has to work with before being locked out by fortifying already captured nodes, making them take longer for the enemy security to capture them - the Hacking: Fortify augmentation will be helpful for this.

Jensen can hack multiple nodes simultaneously and can hack every available node at the same time, provided the player is fast enough. This unlocks multiple routes, but if the chance of detection is high, sometimes working along only one path is a better option. Jensen can also fortify and capture nodes simultaneously. Not all nodes can be captured however - nodes have different security levels, with each subsequently higher level taking longer to capture and carrying a higher chance of detection, some security nodes may be even connected only via a one-way connection, making them impossible to capture. Terminals and computers themselves will also have a starting level of security that Jensen must meet before being able to even access the hacking map. Jensen will only have Level 1 access to begin with, further levels must be unlocked with the Hacking: Capture augmentation.

Aside from critical and security nodes, there are also many other types of nodes. The following nodes are represented by gears and serve to assist the player in hacking: In addition to whatever bonuses Jensen gets from captured datastores, he will also always gain experience points from hacking: Please note, that there is no bonus for using software and/or avoiding setting off the alert. To make hacking easier, Jensen will also come upon hacking software that can be used during the minigame. These come in two varieties. Nuke viruses will instantly capture any node with a 0% chance of detection. Stop worms will temporarily freeze the enemy security trace, even if it is currently in the middle of capturing nodes. These worms can be stacked for a consecutive duration. There are also auto-hacking devices, available in certain preorder editions of the game, that can be thrown like grenades onto terminals or computers to hack them instantly without need for the minigame. Of course, using such a device will not give any exp.
 * Blank nodes, represented by a folder icon, serve only to provide a pathway for the player to travel to critical nodes.
 * Datastores, represented by cubes, provide a bonus to the player when captured. This bonus can be additional EXP, credits, or hacking software.
 * Clearance nodes reduce the security level of all datastores on the map by 1.
 * Soften nodes reduce the security level of all adjacent nodes by 1.
 * Transfer nodes will increase the security level of a random node by 2, and decrease the security level of another random node by 2.
 * Spam nodes will slow down the enemy security trace, giving the player additional time.
 * Successfully hacking a level 1 system will give 25 Exp ("Script Kiddie")
 * Successfully hacking a level 2 system will give 50 Exp ("Gray Hat")
 * Successfully hacking a level 3 system will give 75 Exp ("Black Hat")
 * Successfully hacking a level 4 system will give 100 Exp ("L33t Sk1llz")
 * Successfully hacking a level 5 system will give 125 Exp ("Master Hacker")

While hacking, Jensen will become visible and exposed, regardless of his position when first accessing the terminal or computer. Enemies can and will fire upon Jensen in this state, and sustaining any damage will knock him out of the hacking map. It is therefore advisable to work extremely fast when hacking in dangerous areas. Also, if cloaking is unavailable or insufficient, you can also use boxes or other obstacles to block the sightlines of those who can see you, including cameras, turrets, etc.

In mission hubs, successfully hacking a device in front of civilians and neutral NPCs, such as black market shopkeepers and Belltower agents in the first Hengsa visit, will alarm them, causing them to cower or open fire, respectively. There is no risk around "friendly" gang members; anyone who appears green on your map will not bother you.

Hacking is a required skill in the game as Jensen will encounter many Level 1 terminals throughout the course of the main storyline, and higher levels of hacking unlock new areas, items, and a high quantity of credits and EXP. Even after obtaining access codes and passwords that would allow Jensen to bypass hacking, it is still advisable for the player to hack whenever possible, as this will always obtain additional EXP and often credits and software as well. It has not yet been calculated if the exp gained that way are greater than the cost of upgrading the hacking augmentation.

Tactics
The important thing to do when hacking a computer is: Stop. Don't do anything. Just look. Familiarize yourself with the layout. You have time, there is no chance of being detected while doing nothing (at least not by the security server). Answer the important questions: Where are the target nodes? Where are the datastores (if you want them)? Is the security node reachable or behind a one-way path? Which ways will the security node take to reach your point of entry, in case you're noticed (it will always take ALL available paths, so there is no guessing involved here)?

Don't forget, that you are not limited to one action at a time. If there are three reachable nodes you can capture, you can start with the first one and start the 2nd and 3rd one while the first one is still being captured. You could also start to fortify nodes, even if there were a dozen captures going on at the moment. The limit is your ability to press buttons quickly.

The most basic tactic is trying to not raise the alert. This means, always trying to find the easiest way, taking the way with the lowest ranking nodes on it (the lower the rank of the node, the lower the chance to raise the alert). The Hacking: Stealth augmentation is very valuable here, decreasing the chance of being noticed, though the minimum is 15%.

Depending on your play style, you might only want to reach the target nodes as soon as possible or take all the datastores while you go. If possible (i.e. if the security node is not behind a one-way path) it is advisable to capture the security node, because this not only wins the minigame, but also gives you the content of all the datastores.

Fortification can significantly increase the time the security node needs to beat you, once you're noticed - but only if you do it right. On level 1, fortification is only something for the emergency, as the chances of getting noticed are way too high (so I would suggest using it only if already noticed). So if you want to use it, it is highly recommended to update this aug. You can either start fortifying nodes when you're noticed - the emergency way - or right at the start - the defensive way. What you do depends on your personal style. You CAN fortify your point of entry, making this the most basic way to increase the time you have.

Another important hint is the Disconnect button. You always have more than one try, so instead of losing the game, disconnect, if there is no chance of winning. If you have one or more tries left, this will reset the game and you can simply try again. Of course, disconnecting on your last available try will result in losing - an alarm will sound and enemies will be informed. Note there is a bug in the minigame: If you are going to disconnect, press the "Back" button first, then press "Disconnect". This will exit the hacking game without deducting an attempt, so you can never trigger an alarm this way.

The question "How much Capture do I need" isn't an easy one: There are many rank 2 & 3 systems around, while 4 & 5 systems are pretty rare. Especially if you have the pre-order bonus (the Automatic Unlocking Device,) it may be advisable not to take Capture 4 & 5, but instead use codes you found or the device on these systems. A higher Capture augmentation does increase your chances while hacking lower level systems by 10% per upgrade, but the minimum chance of detection is 15%, making them overkill for the majority of the game, as Capture level 4 & 5 is not even recomended without at least level 2 of Hacking: Stealth (it also increases the speed of capture, but it's a small bonus). Note that you get more experience for hacking a higher level system, plus slightly better rewards from the datastores. To maximize XP, you should never use the passcodes and always hack, and always capture all datastores.

And if you are lazy: Save before hacking. Reload when failing the last try. Easy, but boring.

Augmentation
You have three Hacking augmentations available:
 * Hacking:Capture (HC) starts at Level 1 and can be increased by 4 levels to Level 5
 * Hacking:Fortify (HF) starts at Level 1 and can be increased by 2 levels to Level 3
 * Hacking:Stealth (HS) starts at Level 0 and can be increased by 3 levels to Level 3

Basic rules:
 * At start (HC 1, HF1, HS 0), a strength 1 node has a 60% Capture and Fortify detection chance. Every additional node strength (NS) level adds 20% detection.
 * Every increase in Hacking:Capture decreases Capture detection by 10%, but has no effect on Fortify detection levels.
 * Every increase in Hacking:Fortify decreases Fortify detection by 10%, but has no effect on Capture detection levels.
 * Every increase in Hacking:Stealth decreases both Capture and Fortify detection levels by 15%.
 * There is a practical minimum of 15% detection and a maximum of 100% (of course). However, occasionally nodes can be reduced by APIs to strength 0, in which case there is always a 0% chance of detection. There are also a few strength 0 nodes pre-set into early-game terminals.

So, Stealth helps both Capture and Fortify equally, but Capture and Fortify do not help each other at all.

Equations:

Given the constants in the formula (node strength or NS starting at 60% for strength 1, and HC and HF start at 1 but HS starts at 0), detection chances can be stated as:


 * Capture detection = 50 + 20NS - 10HC - 15HS
 * At the beginning of the game (HC 1 and HS 0, or 10% suppression), this simplifies to: 40 + 20NS
 * At max Capture suppression (HC 5 and HS 3; 85% less), this becomes: 20NS - 45. Level 3 nodes are right at the minimal 15% capture detection level and each additional node strength adds 20%.


 * Fortify detection = 50 + 20NS - 10HF - 15HS
 * At the beginning of the game (HF 1 and HS 0, or 10% suppression), this simplifies to: 40 + 20NS
 * At max Fortify suppression (HF 4 and HS 3; 65% less), this becomes: 20NS - 15. Level 2 nodes are right at the minimal 15% fortify detection level and each additional node strength adds 20%.

Observations:

Players can focus on Hacking: Capture, which allows you to hack terminals with higher security levels (but with only a 10% capture detection decrease), Hacking: Stealth, which decreases detection during capture by 15% for each point spend, or both, providing they have enough points.

Improving Hacking: Capture first is ideal: having insufficient hacking ability prevents one from even making an attempt, while one can still attempt hacking a terminal if they have a high detection chance. Simply put, even with a high detection chance, at least being able to attempt hacking a terminal gives the player more flexibility in gameplay.

Hacking: Fortify is last on the list, since the best defense is a good offense - if one can capture without being detected, Fortify unnecessary.

Video
The following guide gives a visual reference to everything the wiki goes over above, along with some commentary to guide you along.