Altars

On every location there are several altars, or called Magic Altars. Altars only appear on the cave suface, i.e. not in ancient ruins. Altars can spawn enemies, provide various magic effects, items or stats changes. Altars appear cross-shaped on map but a 3x3 pale area in the main game interface. To use altars, character have to first step on the 4 ends of the 'cross', like in the picture shown (yellow tiles), and then step on the center tile.

Once an altar is used, it can be rejuvenated for another use by using magic dust on the cross-shaped, 5 tiles of the altar, and of course one will have to step on them correctly again to use it. Altars obtain a new color by random on rejuvenation.

Effects
Altars of different colors provide different effects:
 * Enemies do not appear if the targeted tile is made impassable.
 * In Lava Caves, after using a magic altar, there is chance to summon several imps on the corners of the altar.

More about utilizing altars
Results of using altars can be negative and depend on some factors, e.g. health level, energy level and tile conditions. It is advisable to think before using the altar (although it is true in the entire game).

Just a few simple examples:
 * One with high health and plenty of health potions may want to leave red altar for the time when one drop some health.
 * One with low health may want to do something to prevent the generation of enemies before using red altar.
 * One with both low health/energy and limited replenishing items may want to use magic dust to rejuvenate an altar to have a 1/2 chance to get a red or blue altar.
 * The effect of Luck stat on using altars is unclear. However, after a recent update on altar, one can have ~70% chance of getting positive result at low Luck level.