You can choose any of the mods on the basic mod list whenever your drone gains a new mod. Unless otherwise specified, you cannot install a single mod more than once.
[Level: 1] Select one technological item from Chapter 7: Equipment of no more than light bulk and an item level no higher than your mechanic level. Your drone is equipped with a robotic arm with that item attached and the proper programming to use the item, although it cannot use a tool that requires skill checks unless it also has ranks in the relevant skill (or you have ranks in the relevant skill and the drone is under your direct control).
[Level: 1] Your drone gains resistance to an energy type of your choice— acid, cold, electricity, fire, or sonic—equal to your mechanic level, to a maximum of 10. You can select this mod multiple times. Its effects do not stack; each time you select this mod, it must apply to a different energy type from the list above.
[Level: 1] Your drone gains low-light vision, darkvision to 60 feet, and a +2 insight bonus to Perception skill checks. If your drone has the camera mod, the camera gains these senses as well.
[Level: 1] Your drone gains a climb speed equal to half its land speed. This mod can be applied to only combat and stealth drones.
Melee Weapon Arm
[Level: 1] Your drone is equipped with a robotic arm to which you can affix a one-handed melee weapon, allowing your drone to wield that weapon and attack with it. This weapon cannot be disarmed. Wielding a two-handed melee weapon requires two melee weapon arms. If you do not already have a weapon to equip, you must purchase it separately. Swapping out a weapon in a melee weapon arm requires use of your custom rig and 1 hour of work. You can select this mod multiple times, each time adding an additional melee weapon arm to the drone.
[Level: 1] Your drone is equipped with powerful miniature jets. It can use these jets to jump up to 30 feet as a move action (either vertically, horizontally, or in any combination that does not exceed 30 feet). If applied to a hover drone, these jets instead allow your drone to increase its fly speed by 30 feet for 1 round. Once used, these jets must cool down for 1 minute before they can be used again.
[Level: 1] Your drone has a camera that you can see through using your custom rig as long as your drone is within range. The camera has ordinary sight, and is capable of seeing whatever an ordinary human could see. The camera can also record up to 1 hour of footage, which can be downloaded and viewed using your custom rig.
[Level: 1] Your drone is equipped with two robotic arms with simple hands. They can perform most functions that your arms can perform (such as opening doors, typing on a keypad, wielding a weapon, or attempting skill checks that require manual dexterity), but attacks made with them take a –4 penalty.
[Level: 1] Your drone is equipped with miniature marine jet engines, granting it a swim speed equal to half its land speed. This mod can be applied to only combat drones and stealth drones.
[Level: 1] Your drone’s AI is secured against outside influence. Any attempt to hack your drone takes a –4 penalty, and your drone receives a +4 insight bonus to saving throws against spells or effects that attempt to take control of the drone or otherwise dictate its actions.
[Level: 1] Your drone is equipped with a seat and programming to carry a rider as a combat-trained mount. If you ride your drone, it must be at least your size or larger. To carry another rider, the drone must be at least one size larger than the rider. You can direct your drone mount in battle without attempting Survival checks.
[Level: 1] Choose another skill from the skill unit list. This is a class skill for your drone, which gains a number of ranks in that skill equal to your mechanic level. Your drone also increases its Intelligence score by 2. At 11th level, you can choose this mod a second time as an advanced mod. If you do, choose an additional skill to become a class skill for your drone (this skill doesn’t have to be on the skill unit list). Your drone gains ranks in the skill equal to your mechanic level. Your drone also increases its Intelligence score again by 2.
[Level: 1] Your drone has a secret compartment that can hold a single item of light bulk or smaller. A successful Perception check (DC = 15 + your mechanic level) is needed to notice or find the compartment. Accessing this compartment is a move action.
[Level: 1] One of your drone’s weapon mounts can hold two additional batteries, magazines, or other type of ammunition in addition to its usual weapon and ammunition capacity. Your drone must have the weapon mount mod before selecting this mod. You can select this mod more than once, up to the number of weapon mounts the drone has.
[Level: 1] Your drone gains a +2 bonus to its AC. At 11th level, you can choose this mod a second time as an advanced mod.
[Level: 1] Your drone gains an armor upgrade slot for an armor upgrade (see page 204). If you do not already have an armor upgrade to install, you must purchase one separately. You can install the armor upgrade only if your drone has enough open upgrade slots to meet the upgrade’s requirements. You can select this mod up to four times, each time adding an additional slot.
[Level: 1] Your drone gains one of the following feats as a bonus feat (it must meet all the prerequisites of the chosen feat): Advanced Melee Weapon Proficiency, Basic Melee Weapon Proficiency, Heavy Weapon Proficiency, Longarm Proficiency, Small Arm Proficiency, or Special Weapon Proficiency. You can select this mod multiple times; each time, your drone gains another of the available proficiency feats as a bonus feat.
[Level: 1] You can affix a small arm or another one-handed ranged weapon on your drone, allowing it to wield that weapon and attack with it. This weapon cannot be disarmed. Mounting a longarm, a heavy weapon, or another two-handed ranged weapon requires two weapon mounts. A weapon mount can hold up to two batteries, two magazines, or two of another type of ammunition for the affixed weapon, provided this ammunition is of light bulk or less. Multiple weapon mounts used to affix a single two-handed weapon count as a single weapon mount for the purpose of how much ammunition it can hold. The drone reloads these batteries or magazines automatically, which takes the usual amount of time for the weapon. Spent batteries or magazines are stored within the drone. You can replace all of a weapon mount’s batteries or magazines as a move action. You must purchase separately or already have the weapon and ammunition for use with a weapon mount. You can replace the weapon with any other weapon that meets the criteria for your mount (for example, if you have two weapon mounts, you could replace a longarm with a heavy weapon). Swapping out a weapon in a weapon mount requires use of your custom rig and 1 hour of work. You can select this mod multiple times, each time adding an additional weapon mount to the drone.
[Level: 1] Your drone is outfitted with cargo space. The drone’s Strength score counts as 4 higher for the purpose of how determining much bulk it can carry, but all of this extra bulk must be stored gear and cargo, not mounted weapons, armor mods, or the like. This does not affect the drone’s actual Strength score in any way, merely how much it can carry. Due to its size, a drone might still be unable to carry awkward or unwieldy items.