The playable character in the game currently has 3 stats (4 in The Escapists 2,) each of which has a maximum level of 100.
The values of these stats can be viewed for the player by pressing the P or 7 (or start on xbox360, left directional pad on PS4) key. Moving the mouse cursor over the bars will show you their numeric value. The player's stats will gradually decrease over time, requiring the player to continue training in order to maintain them. When sent to solitary, all skills drop by a hefty amount. A players stats cannot drop below 10. And, a players stats are all automatically set to 30 when they first enter a prison.
SPD (Speed) / Fitness (Escapists 2)
The treadmill, used to train the Speed stat.
Determines how often a character attacks when fighting. A higher Speed decreases the time between attacks, increasing the character's damage per second. To increase the character's speed, the player will have to either run on the treadmill, skip, use the yoga mat, or hit the speedbag. Note that speed doesn't affect the walking speed of the character.
STR (Strength)
The weight-lifting bench, used to train the Strength stat.
Strength greatly increases your damage in fights and increases your overall health. It can be increased by working out on the weight lifting machines, workout mats or the punching bag in the prison workout area. It's a good idea to build up your strength so you can hit harder and live longer in fights. Like other stats, it will decrease over time and in Solitary, so it is important to continue working out constantly (~25 reps every day should be good) to keep in top condition. To fight better you should have high speed as well. Strength training will increase your Fatigue level quickly, forcing you to wait, shower, eat a meal at mealtime, use something that decreases fatigue, or sleep at lights out.
Intelligence
Intelligence is raised by using the computers or reading books. This stat is needed to be at certain levels for certain jobs and crafting certain items. This increases fatigue, or in The Escapists Console/Mobile and The Escapists 2, decreases stamina.
OPN (Opinion)
The player itself does not have this stat on their profile screen. Rather, every other character in the game has a value for this, which denotes their opinion of the player. Characters that have a low opinion of the player are more likely to attack without being provoked, and will also snitch on the player if they catch them escaping. Guards with a low opinion will tear down posters and bedsheet curtains placed by the player. When opinion of an inmate reaches 80 or higher, you can recruit them by pressing "Q" while near them. A recruited inmate will attack any inmate or guard that either you target, or that attacks the player.