Hooks

Hooks are a classification of Tools that aid the player in traversing the terrain or Terraria. Each hook will fire a hook on a chain that extends a distance from the center of the player's position specific to the type of hook the character is using. If the hook hits a solid block or a platform, then the player will immediately be pulled in a direct line (disregarding gravity entirely) as close to the hooked block as possible, naturally preferring to put the center of the player character horizontally to the left or right of the block grappled.

Pressing the Grapple hotkey (default: E or Xbox:RT) will activate whichever hook the player has. The hook need only be in the player's inventory for the Grapple hotkey to function, and does not need to be in the hotbar. In the iOS game, dragging quickly from the player outwards will cast the projectile in that direction (again, the hook does not need to be in the hotbar).

Hooks, especially the basic Grappling Hook, or possibly some of the gem-related hooks, if the player was lucky in finding gems, are some of the first major jump-boosting items players can gain, and can offer significantly more control than the jump-boosting accessories that the player can obtain at similar times.

As with many mobility-boosting items in Terraria, the hook boosts the effectiveness of other mobility items, rather than being made obsolete by them. Hooks reset player's jump/flying, as if they had touched foot on land again. This works the instant the player hooks a block, even before being pulled in. A player with a great amount of jumping/flying power due to Accessories like Wings can grapple to touch a block, and then immediately start flying again before being pulled more than a foot towards the hooked block as a technique to greatly enhance their flight distance.

Some advanced hooks, such as the Ivy Whip, have multiple hooks that can be used to hook multiple blocks at the same time. If the player hooks a block, and then hooks another block, the player will be suspended at a point at the "averaged" mid-point of all the hooks. (Or as close as possible if there are obstacles in the way.) The hooks are stopped by blocks, but the chains are capable of passing through other blocks. Using multi-hook hooks can be used for careful positioning, allowing the player to hook a ceiling tile, then a floor tile, in order to suspend the player above certain locations. This is useful both for placing walls in open spaces, and in hanging above dangerous locations, like lava, to collect loot without falling in.

If the player has multiple hooks, the hook in the "earliest" position in inventory (reading it from left-to-right, and then top-to-bottom) is the hook that gets used. If the player changes what hook is in inventory in that slot, then existing hooks will still be active, but subsequent grapples will use the hook that is now in the earliest slot in inventory. If the player uses a multi-hook tool, like the Web Slinger, and fires multiple hooks, then changes to a single-hook tool, like the basic Grappling Hook, then grapples again, the earliest Web Slinger hook disappears, but all others remain until the player jumps again.

When dealing with water, for the purposes of activating "breath meters", the player is "above water" when pixel right above their eyes are not in water, and "under water" when that pixel collides with water. This usually translates into being the bottom pixel of the third "tile" of height the player has. Due to how water is in its own layer, and how (due to bugs, see below,) players can slip partially into tiles, this can sometimes cause players to start drowning when "in dry air" because their head is pushed into a block that is covering water. (In console versions, and pre 1.2.1-versions, this is the top of the player's head. This caused drowning bugginess, so it was changed.) In general, grappling a block at the level of the water allows a player to keep their head above water.

Each hook has its own specific characteristics of range, hook velocity, and number of hooks deployable, both at once, and while already hooking a block.

Varieties
These are the 13 hooks currently available: It should be noted that the given reach of these hooks is the effective horizontal distance travelled by the hook from the player, not the distance from the origin.

Tips

 * Grappling a platform with only one hook will pull the player inside the platform, meaning that the player will always hit that platform with subsequent grapples. You must jump to dislodge the hook, and aim at other blocks.
 * The Ice Rod can be exploited in conjunction with the ability to reset flight/jumping accessories; By placing a block that can be grappled mid-flight, resetting flight time, and allowing functionally indefinite flight time for as long as the player can successfully manage to place blocks and grapple them accurately.
 * Characters that have hooked a block are immune to gravity and knockback. As a strategy, some players purposefully grapple the ground in dangerous locations, such as near lava, to ensure they don't fall in if they take damage from an enemy.
 * Players can also exploit immunity to gravity by "grappling the ground" to prevent fall damage. Be careful of using this trick recklessly, as the grappling hook will not function if it reaches the extent of its chain without hitting a block (the game counts it as a "miss" and doesn't check for collision with blocks on the return,) and - depending on the hook used - may prevent you from firing another hook to save yourself until the chain has fully retracted.
 * A player can also exploit the speed of the hook's pulling the player towards a block, and the ability to jump in the middle of the pull to "kickstart" horizontal-speed-boosting items like the Hermes Boots or its derivatives.
 * Grappling a door and then opening it dislodges the hook, and flings the player towards the door at grapple speeds. This can similarly be exploited to "kickstart" Hermes Boots.
 * Multi-hook hooks are more useful for utility purposes, but tend to be less useful for quick transit.