Stealth works in a rather limited manner in REKT. REKT is very much not a stealth game, but you can still try to use disguises and stealth. Stealth rolls the player's Maneuverability and Speed against the enemy's Perception and Intuition, with bonuses and penalties calculated as follows:

Situation Bonus
In the shadows +0.25
In total darkness +0.5
Stealth cloak +1
No atmosphere +0.5
In fog or smoke +0.5
Out of immediate line of sight +1
Somewhere lit -0.25
Somewhere well-lit -0.5
In immediate line of sight -0.5
Making a loud noise -0.5
Firing a weapon (add "loud noise" if weapon makes noise) -0.5
No obstruction -0.5
Scanner or IR-viewer -1

(((Player Agility + Player Speed) - (Enemy Perception + Enemy Intuition)) / 2, rounded down) + (stealth bonus rounded down)

The die is then rolled on the above, and regular rules apply.