|Basic (4 pt): Adds 3 more trip mines to your inventory.|
|Ace (8 pt): Trip mines can now be converted to shaped charges, used to breach certain safes and doors.|
After purchasing the Ace rank of this skill, previously uninteractable C4 icons on objects will become usable (with the standard Interact key) so long as you are carrying trip mines. Placing a shaped charge consumes one trip mine, and all C4 spots on an object must be 'filled' in order to open the object in question. In most cases, this may be only one (as in doors and small '1x1' safes), but it can be up to four for the largest safes.
This skill is not required to place the C4 in any missions where the placement of C4 is a required objective, such as Hotline Miami.
Shaped Charges are handy in many situations. They are mostly used to open safes, doors, armored cars (note that exploding the doors will also destroy the closest 2 safes inside), basically just about anything that can accept a Shaped Charge. Using Charges rather than the OVE9000 also gives a team the advantage of each carrying two weapons while being able to quickly pass through obstacles. The quick application along with a relatively short fuse time means that the whole crew can bust up loot containers (e.g the trucks in Day 1 of Firestarter) and flee with the secured items in short order, sometimes even before the police can arrive.
Do note that, Shaped Charge detonations are very loud and can potentially be a major hamper when going for stealth if civilians and guards are not controlled first. The high tier requirement and cost of the skill may also be an issue, as this will likely be a late-game addition and only by acing the skill can a player place a charge, thus potentially leaving their character awkwardly lopsided skill-wise due to the high reservation of upgrade points.