Mechanics

Version Differences

Old Version - Version 1.42.5 and earlier versions.
New Version - Version 1.42.6 and later versions.
In the new versions, all major glitches are fixed, requiring a major change in the route. In addition, new versions do not start you with the Mines key, requiring you to do the quest to obtain it. Using locks is significantly slower in new versions, and there are some minor balance changes across the game.

Movement

Running gives faster horizontal movement than jumping. Jumping gives faster horizontal movement than falling. Jumping gives faster vertical movement than climbing ladders. As such: don't jump when you can run, don't fall off platforms if you can jump off them, and jump up to ladders whenever possible.
Whenever you get hit, you take a small hop backwards. Turning your back to the attacker one frame before impact can turn this into a forward hop, which barely loses any time compared to running. Alternatively, if you jump at an enemy and turn your back while in mid-air, the hop is completely cancelled, and you only take the slowdown from jumping. This latter technique works better against slow enemies, such as maggots.

Phase Door

The Scroll of Phase Door is an item bought from Zoran for 25 gold a piece. When used, it teleports you to the far end of the platform you're standing on, without crossing gaps or going up ledges. It completely bypasses enemies as well as any triggers in the process. Due to its long cast time, it is only useful when crossing about 75% of a room's size in distance, or when skipping cutscenes or enemies, and its high cost makes it a scarce resource in the early game.

Speed Potions

Speed potions improve your running speed as well as your attacking speed. They do not improve jumping speed, falling speed, climbing speed, spellcasting speed, or scroll casting speed. As such, only use them for their running speed increase, preferably in areas that are not otherwise sped up by phase doors.

Pets

Pets will target the nearest hostile monster they can hurt and attack it as long as they have energy. Their AI cannot be controlled in any way, but their position can be altered to some extent which can affect who (and whether) they attack. Pets generally try to face the same way as Daniel, but they turn very slowly unless movement forces them to turn around, and if they're busy attacking an enemy, they won't shift their facing direction at all, which can both be a advantage or a detriment to controlling them.
Pets can be dismissed and resummoned instantly while you are standing or running (not while jumping or climbing). When resummoned, they are fully healed but lose all energy.
Kills made by pets do not award experience, so make sure to dismiss your pet when farming exp to not accidentally miss out.

Resets

Saving and reloading the game has the following effects:

• All monsters respawn and reset to their default position.
• All elevators reset to their default position.

As elevators run on a global timer, it may be beneficial to reset before any televator glitch uses to ensure a good position to execute the glitch. Generally you cannot be certain at what position the elevator is without a reset, which may cost time.

Glitches

All of these glitches only work on old versions of the game.

Televator

Using a teleportation skill while on an elevator will confuse the game about the destination of the teleport, allowing for certain sequence breaks. The televator glitch comes in two varieties:

• Scrolls: When using scroll-based teleportation skills while standing on an elevator, your vertical position on arrival will be the same as the vertical position at the end of the cast. This can easily put you out of bounds, either on top of or beneath the destination room. Both the Return scroll and Shop teleportation scrolls work for this glitch.
• Spells: Using a spell-based teleportation skill on the same frame as you land on an elevator will instead teleport you to the room below the destination - unless the destination is on the bottom row of the map, in which case you will teleport to the room above it. This glitch works with the infinite teleportation items (such as the Halo) as well as the Alteration teleportation skills. Unlike the scroll version, it is not very consistent.

Infinite Attacking

By mashing the Use key while swinging a weapon, the swing animation freezes at its last active frame. When used with a Polearm class weapon, it will continuously do damage at a rate of one hit per second; this hit rate is unaffected by any increases or decreases in attack speed.

Simulcasting

You can attack with any equipped weapon while casting any spell. This is most effective when combining the Fireball spell with the bow, allowing you to combine their damage output with a small decrease in cast/attack speed, giving a substantial increase in DPS. The glitch works with any spell and any weapon, however.

Damage Multipliers

Spell damage increases stack multiplicatively, which means that stacking several sources of damage increases (i.e. a robe, a candle and a staff) can offer significant increases in spell damage.