Bonus roll

The bonus roll system, introduced in patch 5.0, allows a player to receive an additional roll against a boss's loot table, giving the player an extra chance to receive an item.

Upon completing a raid encounter for the first time in the week, if the player has the appropriate token for that raid, a window will appear where the player has the option to use a token for a bonus roll or pass. The result is either gold or an item off the boss's loot table that is appropriate for their loot specialization.

While the odds of receiving an item on the first bonus roll are the same as the kill, whenever the player receives gold the odds of receiving an item on subsequent bonus rolls are slightly increased until the player receives an item, at which point it resets to the normal rate.

The use of a bonus roll token is strictly a personal endeavor and will not interfere with any other player's loot roll. It creates a completely separate roll against the boss's loot table.

As of patch 5.2, a player with dual talent specialization may switch to the other spec before rolling to get gear appropriate to their other spec; also, the addition of loot specializations in patch 5.3 made it even easier to control what spec they will get loot for. Players who want items for an off-spec may choose in the UI which spec they would like to receive loot for from bonus rolls or quest rewards, regardless of the player's current specialization.

Loot rolls are not available for Shadowlands-era content.

Tokens
The following contemporary dungeons, raids and world bosses support bonus rolls with the following tokens.

Mists of Pandaria

 * Elder Charm of Good Fortune: Mogu'shan Vaults, Heart of Fear, Terrace of Endless Spring, Salyis's Warband and Sha of Anger
 * Mogu Rune of Fate: Throne of Thunder, Nalak and Oondasta (added in patch 5.2)
 * Warforged Seal: Siege of Orgrimmar, Chi-Ji, Niuzao, Xuen, Yu'lon, and Ordos (added in patch 5.4)

Warlords of Draenor

 * Seal of Tempered Fate: Highmaul, Blackrock Foundry, Drov the Ruiner, Tarlna the Ageless, and Rukhmar
 * Seal of Inevitable Fate: and Supreme Lord Kazzak (added in patch 6.2.0)

Legion

 * Seal of Broken Fate: For all Legion dungeons, raids, and world bosses

Battle for Azeroth

 * Seal of Wartorn Fate: For all Battle for Azeroth dungeons, raids, and world bosses

Shadowlands
There is no current plan to add a bonus roll token for this expansion.

Strategy
Deciding when to spend bonus roll tokens can take some thought.

You certainly want to save the tokens for use on a boss that has a chance to drop loot you need. If you already have all the gear from a boss (or better gear) then spending a charm will either give you gold or a redundant piece of gear to vendor. If you expect to defeat another boss who can drop an item you do need, then you usually want to save the charms for that other boss.

If you are raiding normal level content regularly, you probably don't want to spend tokens in LFR. The exception is if you defeat fewer than 3 normal-mode bosses per week, then your tokens will accumulate and it is reasonable to spend the excess tokens on LFR bosses.

If you are raiding normal content (as opposed to LFR) and the boss actually drops an item that is an upgrade for you such that you would choose the need option you are faced with a small dilemma: should you spend a charm for an extra independent roll or not? If you spend a token there is a small chance you will win the item from the regular roll and the exact same item from the bonus roll. If you were rolling against a teammate you can trade the normal mode loot to them. If you were the only one who needed that loot now you have two and will probably sell the redundant one. If you do not have excess charms it is probably best to skip the bonus roll and hope to win the roll on the normal loot.

The bonus roll timer is 3 minutes, so as long as your group decides loot quickly, you can afford to delay your bonus roll until loot is assigned. Additionally, you will still get your chance to make a bonus roll even if you are disconnected at the end of the fight, as long as you log back in within the timer.

If you don't do enough daily quests to complete the conversion quest every week you probably want to spend them sparingly and only on bosses that drop best-in-slot upgrades.

Summary:
 * If you have 8 or more charms and are doing enough daily quests to replace them, and don't need to save some for a normal-mode raid, you can spend them on LFR bosses that drop loot that is still an upgrade.
 * If you have at least 5 charms, only spend them on normal-mode bosses who can drop upgrades for you.
 * If you have less than 5 charms, only spend them on normal-mode bosses that can drop best-in-slot items for you.

Limitations
All Pandarian and Draenic world bosses may only have a bonus roll used against their loot table once each week. The same applies for end-of-instance bosses in Raid Finder mode, such as Lei Shen, or the Sha of Fear. Other bosses in Raid Finder mode may have a bonus roll used against them as many times as the player has enough tokens to do so.

Bad luck streak protection
Patch 5.3.0 added bad luck streak protection to bonus rolls.

Whenever you use a bonus roll and you don’t get any loot, your chance of getting loot on the next roll will increase. This increased probability won’t be reset until some loot is awarded, and this is independent of the boss that is being killed. The bad luck streak protection will carry over and continue to increase the probability from boss to boss and instance to instance and won't reset until you get some loot. Basically, this feature treats all bonus rolls as if they were actually the same, no matter where they originate from.