Here is a place where you can list alterations for starting PCs in Gigacrawler, the game we're making.
Since, unlike spells, devices and martial arts, PCs have the option to choose which (if any) of these alterations their PC has this list must be more balanced than the others. No option should be obviously way better or worse than the others.
If an alteration is a cyborg implant or robot part, it is presumed to have a tech level of 10 or a tech level equal to the PC's own, whichever is higher. The PC is presumed to be able to operate any modifications she starts with, however, and the tech level only comes into play in certain situations (someone attempts to modify it, Gigacrawler Alterations (adaptations, mutations, and modifications for nonhumans, mutants, robots, and cyborgs)someone throws a Coldbringer grenade, etc.). It is possible for characters to acquire implants with tech levels higher or lower than their own later in the game, and, even if they are higher, the PC will be able to use them.
A GM may opt to allow a PC to have extra alterations if the character chooses negative alterations that have a genuine practical effect (only one arm, blind, etc.). A wildly generous GM may allow a PC to have any other extra (a skill, or a randomly determined spell, martial art, or piece of equipment) in exchange for such a handicap. At some point we may make a separate page for such "negative alterations".
If you are creating a character with alterations, you can count the results here and use this to randomize which alterations your PC has or just pick ones you like.
1. Claws: Add 3 to the strength of unarmed attacks
2. Spikes or spurs on body: Successful unarmed strikes from a foe cause a weapon strength 4 attack back at that foe.
3. Can survive without food indefinitely. (Player must name alternate fuel source.)
4. Insect eyes/scanners: +1 to initiative for whole group. (Doesn't stack with other members of group.)
5. Eats metal. (No faster than a human eats meat.)
6. Can survive without water indefinitely. (Player must name alternate fuel source.)
7. Needs half as much food and water as a human.
8. Tough species/model: Add 2 to physique, subtract 1 from agility.
9. Nimble species/model: Add 2 to agility, subtract 1 from physique.
10. Thick hide: skin has 3 points of armor built in.
11. Antichaotic species/built-in reality stabilizer: Magic has 50% of failure within 5 feet of creature. PC's magic level must be 4 or less. Lost points may be added to tech level.
12. Detachable/throwable head. Flying bite attacks are possible. Can be thrown current physique +5 feet.
13. Detachable/throwable hand. A line of cartilage, filament or cord may connect the PC to the hand if desired or the hand may be completely "free", but the PC must decide during character generation. can be thrown physique x 2 feet.
14. Eats chaos: If any opposed roll by anyone at the table results in 1 and 10 being rolled simultaneously, the PC gains a re-roll to use whenever s/he likes.
15. Extra limb: PC is allowed one extra non-attack, non-spellcasting action per round if it can be
plausibly performed by the limb.
16. Two extra limbs: PC is allowed one extra action (including an attack but not including spellcasting) during combat if it can be plausibly performed with the extra limbs. However the extra limbs make the PC too unwieldy to effectively dodge ordinary combatants so s/he does not add his or her agility when rolling against an opponent's to-hit roll (other modifiers may still be applied, and the defender still gets to roll). The multi-limbed PC may dodge attacks made from more than 40 feet away normally, though the roll is made at -2.
17. Variable weapon mount. A successful tech check against a handheld weapon's tech level and a successful intelligence roll against it allows any hand-held weapon to be modified to fit this mount. The attached weapon can be used at a +3 to hit. Only available as a robot modification or cybernetic.
18. Chaintread. The PC has a narrow chainsaw-like blade installed in his/her lower arm, leaving an row of exposed teeth running from wrist to elbow on the outer forearm. It can be used to make a melee attack with weapon strength = current physique + 5 but the attack is awkward (- 3 to hit). The more common use is as a parrying device--if the PC rolls a 7 or above (and succeeds) when avoiding a melee attack, this is counted as a parry with the chaintread and whatever the attacker was trying to hit the PC with takes 8 points of damage (no roll--the attacker is effectively shoving his/her weapon or fist into a chainsaw.) Only available as a robot mod or cybernetic.
19. Unusual internal anatomy. Internal organs are wherever the player says they are. The PC should secretly write down where his her various organs are--especially his/her brain, and heart/power source are (though announce s/he has this alteration). Whenever the DM announces (or it is otherwise determined) that a particular body part is seriously wounded, the PC must reveal the locations.
20. Hovering. The PC hovers instead of walking. Speed is as walking.