A standard simulation-style adaptation of the tabletop mahjong game, Tel-Tel Mahjong is notable for being one of the few games to support the Sega Mega Modem peripheral, allowing players to play against each other through a dial-up connection (with two human players and two CPU players). The game also includes a campaign mode against a series of CPU opponents.
SUNSOFT later used the "Tel-Tel" name, as well as the dial-up multiplayer concept, for the professional baseball game Tel-Tel Stadium.
All settings are enabled unless otherwise specified.
- 食い断么 (Kui-tanyao) - Allows the tanyao (no terminal or honor tile) yaku to be counted with an exposed hand.
- 不聴罰 (Noten-batsu) - After an exhaustive draw, players without a tenpai hand must give penalty points to those with a tenpai hand.
- ウラドラ (Uradora) - An additional dora is revealed in the event that a riichi-declared hand has won.
- 槓ウラドラ (Kan-uradora) - An additional uradora is revealed for each kandora in play. Disabled by default, and cannot be enabled if Uradora is disabled.
- 一発 (Ippatsu) - After declaring riichi, players can receive an additional yaku if they receive a winning tile within an uninterrupted set of opponent tile draws.
- 西入 (Nishiiru) - If the top player does not reach 30,000 points by the end of the second round (South), the game plays a third round (West).
- 二飜しばり (Nihan-shibari) - If a player has remained the dealer for five consecutive hands (with exhaustive draws and/or dealer wins), players must have a yaku with at least two-han to declare the next win.
- 南場不聴 (Nanba-noten) - If a hand in the South round ends in an exhaustive draw with the dealer not in tenpai, either repeat the hand with the same dealer (連荘, renchan, default) or progress as normal (輪荘, ronchan).
- 自模平和 (Tsumo-pinfu) - ?
- 三連刻 (Sanrenkou) - Allows an additional two-han yaku with three sequential triplets of the same suit. Disabled by default.
- 四連刻 (Suurenkou) - Allows an additional yakuman with four sequential triplets of the same suit. Disabled by default.
- 大車輪 (Daisharin) - Allows an additional yakuman with a closed hand of all sequential non-terminal pairs of the same suit. Disabled by default.
- 八連荘 (Paarenchan) - Players who win their eighth consecutive hand receives an automatic yakuman on their eighth win. Disabled by default.
- 数え役満 (Kazoe-yakuman) - Players whose hand has 13 han or more receives an automatic yakuman. Disabled by default.
- ダブル役満 (Double-yakuman) - Allows certain hands to score double the yakuman amount. (UNKNOWN: Allows stacked yakuman?). Disabled by default.
- 二盃口 (Ryanpeikou) - Changes the han value of double ippeikou (two sets of identical sequences) to either three (三飜, default) or two (二飜).