Game logic

Game rules

What the game allows and how far: the team, the monsters and items you can keep, levels and experience, and what happens when you lose.

The team

Isaac always takes part and cannot be left out. Up to 3 squads go with him, never more than the map’s start points: almost every battle has 3, a few have 1 or none.
Each species makes squads of 1, 2 or 3 units; the player does not choose. On the field, the player has at most 10 units.
A squad’s units start at its start point, moved by (-22, 8), (22, 8), (0, -14) px (y grows downwards).
Each unit costs UP (its unit page shows how much). The team’s total cannot go over the capacity, which grows with Isaac’s level. Only the team editor checks it; battles do not.

UP the team can hold
Isaac’s level	1–3	4–6	7–9	10–12	13–15	16–18	19–21	22–24	25–27	28–50
UP	2	3	4	5	6	7	8	9	10	11

Up to 65 are kept. Several of the same species are allowed.
Only regular enemies can be captured: not bosses, not allies.
Up to 32 captures per battle count; the rest are lost.
They join after the battle is won, at the level they had in it and with 0 EXP. They do not fight in the battle where they were caught.
With the list full, the new one replaces a monster that is not in a squad, or is let go.
A monster can be released from the team screen.

The inventory has 10 slots. Repeated items are allowed, also the same item at different levels.
Each squad carries one item, which works on every unit in it. Isaac carries none.
Items come from chests, at levels 1 to 6. Their level never rises afterwards. Up to 32 items found per battle count.
With the inventory full, the new item replaces one that is not equipped, or is thrown away.
There is no money and no shop: nothing is bought or sold.

Isaac and the monsters reach level 50 at most. Enemies too, and each of Isaac’s elements goes from 1 to 50.
Experience comes only from deaths: every enemy, boss or ally on the map that dies gives 10 × its level, whoever kills it. Captured monsters give nothing.
A battle gathers 9,999 EXP at most. On a win, Isaac and every squad of the team each get the whole amount; it is not split.
Going from level 1 to 50 takes 316,905 EXP. Stats are not stored: they come from the level when each battle starts.

Isaac starts drawing 1 rune per spell. «Battle 004 (ch. 2)» / «Battle 005 (ch. 2)» lets him chain 2, and «Town 013 (ch. 5)» 3.
There is no limit of active spells and no cooldown: Isaac can cast again as soon as the previous cast animation ends. MP is the only limit.

The game takes a checkpoint each time a mission, a town scene or a free battle starts from the map. Battles inside the mission and saving do not take one.
After a defeat or a draw nothing from that battle is kept: no experience, captures, items or new spells.
Continuing puts the story and the runes back to the checkpoint and Isaac back on the map spot he came from. His level, monsters and items stay as they were.
The mission is on the map again and replays from its start with all its battles: losing the second one means winning the first one again.
Retiring from the pause menu goes to the title screen with no option to continue: from there you can only load a save or start a new game.
Saving does not move the checkpoint, and there is no autosave. Loading a save makes it the checkpoint.