Immune to psychic and poison damage 

Resistant to fire and cold damage

Vulnerable to Lightning

Immunity to conditions like charmed, exhaustion, frightened, paralyzed, petrified, poisoned, sleep, stunning, and disease

Immune to Mind altering effects (illusions, charm, fear), death effects, necromancy effects 

Automatons come with a standard power supply installed. Each power supply is equipped with a maximum capacity of 10 charges. These charges can be expended for a combat boon but must be recharged or the automaton will be rendered inert. An Inert automaton can only be brought back with a full charge. An automaton can recharge provided a power source is available. Recharging requires a long rest and will restore 1d4+proficiency bonus charges to the automaton provided there is nothing inhibiting the charge. Some negative status effects can effect charge rate and retention. If the long rest is interrupted, such as with a night ambush, recovered charge is halved. If the rest is completed after the encounter, the remaining charge is recovered. While charging, the automaton is not aware of their surroundings, cannot make reactions, all damage dealt to the automaton is critical. After damage is taken, the automaton is "awoken" from this state, otherwise another individual must make a "help" action to reactivate the automaton. If an automaton takes a long rest in which they do not recharge, 1-2 charge naturally is expended.

As a free action, the automaton may expend 1 charge from their power supply to gain haste (1 additional action, +2 AC, doubled movement, and advantage on dex saves) for one round. This effect can only be used if the automaton has more than 1 charge available and can only be used once per round. If the automaton overclocks for two back-to-back rounds they will be temporarily put into "cool-down" making them unable to move or take any actions or reactions for 1 round (similar to lethargy status).

As an action, the automaton may expend 1 charge from their power supply to vent steam creating a cloud that obscures view. This effect can only be used if the automaton has more than 1 charge available and can only be used once per round. 

As a metal construct, you do not bleed and are able to upgrade parts of you with machinery if available. However, you cannot be submerged in water. If fully submerged, you will short out and immediately deplete your power supply of all charge. If submerged partially (i.e. water higher than waist deep) you have a 50% chance of shorting out. If you avoid shorting you, you will not be at risk of shorting out unless you submerge yourself further, or at your current level of submergence for longer than 10 rounds (1 min). 

Being a machine makes it difficult to be charismatic, so charisma checks are made with disadvantage