Currently, only effects giving temporary stat increase as an alteration are present (such as speed_up, strength_up or defense_up).
Nothing for increasing the stats in a more "definitive" way.

It would be nice to add these kind of effects, and why not a few items making use of them.
These effects should not result in the creation of an Alteration (since it would not be temporary), but should rather directly modify the stats of the targeted entities.

Place to add implementation of the effects is effect.py.
Place for defining displayed names is in text.py (effects sub-dictionary in TRANSLATIONS).

No need to bother about translations to other languages than English right now, checking if the game is not crashing when using another language should be sufficient.